Support for Runtime CPU type detection via builtins (issue5754058)

Patch for CPU detection at run-time.

On Wed, Mar 7, 2012 at 1:49 AM, Sriraman Tallam <tmsriram@google.com> wrote:
> Patch for CPU detection at run-time.
> ===================================
>
> Patch for CPU detection at run-time, to be used in dispatching of
> multi-versioned functions.   Please see this discussion:
> http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01355.html
> when this patch for reviewed the last time.
>
> For more detailed description:
> http://gcc.gnu.org/ml/gcc/2012-03/msg00074.html
>
> One of the main concerns was about making CPU detection initialization a
> constructor. The main point raised was about constructor ordering. I have
> added a priority value to the CPU detection constructor to make it very high
> priority so that it is guaranteed to fire before every constructor without
> an explicitly marked priority value of 101.  However, IFUNC initializers
> will still fire before this constructor, so the cpu initialization routine
> has to be explicitly called in such initializers for which I have added a
> builtin: __builtin_cpu_init ().
>
> This patch adds the following new builtins:
>
> * __builtin_cpu_init
> * __builtin_cpu_supports_cmov
> * __builtin_cpu_supports_mmx
> * __builtin_cpu_supports_popcount
> * __builtin_cpu_supports_sse
> * __builtin_cpu_supports_sse2
> * __builtin_cpu_supports_sse3
> * __builtin_cpu_supports_ssse3
> * __builtin_cpu_supports_sse4_1
> * __builtin_cpu_supports_sse4_2
> * __builtin_cpu_is_amd
> * __builtin_cpu_is_intel_atom
> * __builtin_cpu_is_intel_core2
> * __builtin_cpu_is_intel
> * __builtin_cpu_is_intel_corei7
> * __builtin_cpu_is_intel_corei7_nehalem
> * __builtin_cpu_is_intel_corei7_westmere
> * __builtin_cpu_is_intel_corei7_sandybridge
> * __builtin_cpu_is_amdfam10
> * __builtin_cpu_is_amdfam10_barcelona
> * __builtin_cpu_is_amdfam10_shanghai
> * __builtin_cpu_is_amdfam10_istanbul
> * __builtin_cpu_is_amdfam15_bdver1
> * __builtin_cpu_is_amdfam15_bdver2

I think the non-feature detection functions are not necessary at all.
Builtin functions are not exactly cheap, nor is the scheme you invent
backward/forward compatible.  Instead, why not add a single builtin
function, __builtin_cpu_supports(const char *), and decode from
a comma-separated list of features?  Unknown features are simply
"not present".  So I can write code with only a single configure check,
for __builtin_cpu_supports, and cater for future features or older compilers.

And of course that builtin would be even cross-platform.

Implementation-wise I'll leave this to x86 maintainers to comment on.

Richard.

>
>        * config/i386/i386.c (build_struct_with_one_bit_fields): New function.
>        (make_var_decl): New function.
>        (get_field_from_struct): New function.
>        (fold_builtin_target): New function.
>        (ix86_fold_builtin): New function.
>        (ix86_expand_builtin): Expand new builtins by folding them.
>        (make_platform_builtin): New functions.
>        (ix86_init_platform_type_builtins): Make the new builtins.
>        (ix86_init_builtins): Make new builtins to detect CPU type.
>        (TARGET_FOLD_BUILTIN): New macro.
>        (IX86_BUILTIN_CPU_SUPPORTS_CMOV): New enum value.
>        (IX86_BUILTIN_CPU_SUPPORTS_MMX): New enum value.
>        (IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT): New enum value.
>        (IX86_BUILTIN_CPU_SUPPORTS_SSE): New enum value.
>        (IX86_BUILTIN_CPU_SUPPORTS_SSE2): New enum value.
>        (IX86_BUILTIN_CPU_SUPPORTS_SSE3): New enum value.
>        (IX86_BUILTIN_CPU_SUPPORTS_SSSE3): New enum value.
>        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_1): New enum value.
>        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_2): New enum value.
>        (IX86_BUILTIN_CPU_INIT): New enum value.
>        (IX86_BUILTIN_CPU_IS_AMD): New enum value.
>        (IX86_BUILTIN_CPU_IS_INTEL): New enum value.
>        (IX86_BUILTIN_CPU_IS_INTEL_ATOM): New enum value.
>        (IX86_BUILTIN_CPU_IS_INTEL_CORE2): New enum value.
>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM): New enum value.
>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE): New enum value.
>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE): New enum value.
>        (IX86_BUILTIN_CPU_IS_AMDFAM10_BARCELONA): New enum value.
>        (IX86_BUILTIN_CPU_IS_AMDFAM10_SHANGHAI): New enum value.
>        (IX86_BUILTIN_CPU_IS_AMDFAM10_ISTANBUL): New enum value.
>        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1): New enum value.
>        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2): New enum value.
>        * config/i386/i386-builtin-types.def: New function type.
>        * testsuite/gcc.target/builtin_target.c: New testcase.
>
>        * libgcc/config/i386/i386-cpuinfo.c: New file.
>        * libgcc/config/i386/t-cpuinfo: New file.
>        * libgcc/config.host: Include t-cpuinfo.
>        * libgcc/config/i386/libgcc-glibc.ver: Version symbols __cpu_model
>        and __cpu_features.
>
> Index: libgcc/config.host
> ===================================================================
> --- libgcc/config.host  (revision 184971)
> +++ libgcc/config.host  (working copy)
> @@ -1142,7 +1142,7 @@ i[34567]86-*-linux* | x86_64-*-linux* | \
>   i[34567]86-*-kfreebsd*-gnu | x86_64-*-kfreebsd*-gnu | \
>   i[34567]86-*-knetbsd*-gnu | \
>   i[34567]86-*-gnu*)
> -       tmake_file="${tmake_file} t-tls i386/t-linux"
> +       tmake_file="${tmake_file} t-tls i386/t-linux i386/t-cpuinfo"
>        if test "$libgcc_cv_cfi" = "yes"; then
>                tmake_file="${tmake_file} t-stack i386/t-stack-i386"
>        fi
> Index: libgcc/config/i386/t-cpuinfo
> ===================================================================
> --- libgcc/config/i386/t-cpuinfo        (revision 0)
> +++ libgcc/config/i386/t-cpuinfo        (revision 0)
> @@ -0,0 +1 @@
> +LIB2ADD += $(srcdir)/config/i386/i386-cpuinfo.c
> Index: libgcc/config/i386/i386-cpuinfo.c
> ===================================================================
> --- libgcc/config/i386/i386-cpuinfo.c   (revision 0)
> +++ libgcc/config/i386/i386-cpuinfo.c   (revision 0)
> @@ -0,0 +1,306 @@
> +/* Get CPU type and Features for x86 processors.
> +   Copyright (C) 2011 Free Software Foundation, Inc.
> +   Contributed by Sriraman Tallam (tmsriram@google.com)
> +
> +This file is part of GCC.
> +
> +GCC is free software; you can redistribute it and/or modify it under
> +the terms of the GNU General Public License as published by the Free
> +Software Foundation; either version 3, or (at your option) any later
> +version.
> +
> +GCC is distributed in the hope that it will be useful, but WITHOUT ANY
> +WARRANTY; without even the implied warranty of MERCHANTABILITY or
> +FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
> +for more details.
> +
> +You should have received a copy of the GNU General Public License
> +along with GCC; see the file COPYING3.  If not see
> +<http://www.gnu.org/licenses/>. */
> +
> +#include "cpuid.h"
> +#include "tsystem.h"
> +
> +int __cpu_indicator_init (void) __attribute__ ((constructor (101)));
> +
> +enum vendor_signatures
> +{
> +  SIG_INTEL =  0x756e6547 /* Genu */,
> +  SIG_AMD =    0x68747541 /* Auth */
> +};
> +
> +/* ISA Features supported. */
> +
> +struct __processor_features
> +{
> +  unsigned int __cpu_cmov : 1;
> +  unsigned int __cpu_mmx : 1;
> +  unsigned int __cpu_popcnt : 1;
> +  unsigned int __cpu_sse : 1;
> +  unsigned int __cpu_sse2 : 1;
> +  unsigned int __cpu_sse3 : 1;
> +  unsigned int __cpu_ssse3 : 1;
> +  unsigned int __cpu_sse4_1 : 1;
> +  unsigned int __cpu_sse4_2 : 1;
> +} __cpu_features;
> +
> +/* Processor Model. */
> +
> +struct __processor_model
> +{
> +  /* Vendor. */
> +  unsigned int __cpu_is_amd : 1;
> +  unsigned int __cpu_is_intel : 1;
> +  /* CPU type. */
> +  unsigned int __cpu_is_intel_atom : 1;
> +  unsigned int __cpu_is_intel_core2 : 1;
> +  unsigned int __cpu_is_intel_corei7 : 1;
> +  unsigned int __cpu_is_intel_corei7_nehalem : 1;
> +  unsigned int __cpu_is_intel_corei7_westmere : 1;
> +  unsigned int __cpu_is_intel_corei7_sandybridge : 1;
> +  unsigned int __cpu_is_amdfam10h : 1;
> +  unsigned int __cpu_is_amdfam10h_barcelona : 1;
> +  unsigned int __cpu_is_amdfam10h_shanghai : 1;
> +  unsigned int __cpu_is_amdfam10h_istanbul : 1;
> +  unsigned int __cpu_is_amdfam15h_bdver1 : 1;
> +  unsigned int __cpu_is_amdfam15h_bdver2 : 1;
> +} __cpu_model;
> +
> +/* Get the specific type of AMD CPU.  */
> +
> +static void
> +get_amd_cpu (unsigned int family, unsigned int model)
> +{
> +  switch (family)
> +    {
> +    /* AMD Family 10h.  */
> +    case 0x10:
> +      switch (model)
> +       {
> +       case 0x2:
> +         /* Barcelona.  */
> +         __cpu_model.__cpu_is_amdfam10h = 1;
> +         __cpu_model.__cpu_is_amdfam10h_barcelona = 1;
> +         break;
> +       case 0x4:
> +         /* Shanghai.  */
> +         __cpu_model.__cpu_is_amdfam10h = 1;
> +         __cpu_model.__cpu_is_amdfam10h_shanghai = 1;
> +         break;
> +       case 0x8:
> +         /* Istanbul.  */
> +         __cpu_model.__cpu_is_amdfam10h = 1;
> +         __cpu_model.__cpu_is_amdfam10h_istanbul = 1;
> +         break;
> +       default:
> +         break;
> +       }
> +      break;
> +    /* AMD Family 15h.  */
> +    case 0x15:
> +      /* Bulldozer version 1.  */
> +      if (model >= 0 && model <= 0xf)
> +        __cpu_model.__cpu_is_amdfam15h_bdver1 = 1;
> +      /* Bulldozer version 2.  */
> +      if (model >= 0x10 && model <= 0x1f)
> +        __cpu_model.__cpu_is_amdfam15h_bdver2 = 1;
> +      break;
> +    default:
> +      break;
> +    }
> +}
> +
> +/* Get the specific type of Intel CPU.  */
> +
> +static void
> +get_intel_cpu (unsigned int family, unsigned int model, unsigned int brand_id)
> +{
> +  /* Parse family and model only if brand ID is 0. */
> +  if (brand_id == 0)
> +    {
> +      switch (family)
> +       {
> +       case 0x5:
> +         /* Pentium.  */
> +         break;
> +       case 0x6:
> +         switch (model)
> +           {
> +           case 0x1c:
> +           case 0x26:
> +             /* Atom.  */
> +             __cpu_model.__cpu_is_intel_atom = 1;
> +             break;
> +           case 0x1a:
> +           case 0x1e:
> +           case 0x1f:
> +           case 0x2e:
> +             /* Nehalem.  */
> +             __cpu_model.__cpu_is_intel_corei7 = 1;
> +             __cpu_model.__cpu_is_intel_corei7_nehalem = 1;
> +             break;
> +           case 0x25:
> +           case 0x2c:
> +           case 0x2f:
> +             /* Westmere.  */
> +             __cpu_model.__cpu_is_intel_corei7 = 1;
> +             __cpu_model.__cpu_is_intel_corei7_westmere = 1;
> +             break;
> +           case 0x2a:
> +             /* Sandy Bridge.  */
> +             __cpu_model.__cpu_is_intel_corei7 = 1;
> +             __cpu_model.__cpu_is_intel_corei7_sandybridge = 1;
> +             break;
> +           case 0x17:
> +           case 0x1d:
> +             /* Penryn.  */
> +           case 0x0f:
> +             /* Merom.  */
> +             __cpu_model.__cpu_is_intel_core2 = 1;
> +             break;
> +           default:
> +             break;
> +           }
> +         break;
> +       default:
> +         /* We have no idea.  */
> +         break;
> +       }
> +    }
> +}
> +
> +static void
> +get_available_features (unsigned int ecx, unsigned int edx)
> +{
> +  __cpu_features.__cpu_cmov = (edx & bit_CMOV) ? 1 : 0;
> +  __cpu_features.__cpu_mmx = (edx & bit_MMX) ? 1 : 0;
> +  __cpu_features.__cpu_sse = (edx & bit_SSE) ? 1 : 0;
> +  __cpu_features.__cpu_sse2 = (edx & bit_SSE2) ? 1 : 0;
> +  __cpu_features.__cpu_popcnt = (ecx & bit_POPCNT) ? 1 : 0;
> +  __cpu_features.__cpu_sse3 = (ecx & bit_SSE3) ? 1 : 0;
> +  __cpu_features.__cpu_ssse3 = (ecx & bit_SSSE3) ? 1 : 0;
> +  __cpu_features.__cpu_sse4_1 = (ecx & bit_SSE4_1) ? 1 : 0;
> +  __cpu_features.__cpu_sse4_2 = (ecx & bit_SSE4_2) ? 1 : 0;
> +}
> +
> +
> +/* Sanity check for the vendor and cpu type flags.  */
> +
> +static int
> +sanity_check (void)
> +{
> +  unsigned int one_type = 0;
> +
> +  /* Vendor cannot be Intel and AMD. */
> +  gcc_assert((__cpu_model.__cpu_is_intel == 0)
> +             || (__cpu_model.__cpu_is_amd == 0));
> +
> +  /* Only one CPU type can be set. */
> +  one_type = (__cpu_model.__cpu_is_intel_atom
> +             + __cpu_model.__cpu_is_intel_core2
> +             + __cpu_model.__cpu_is_intel_corei7_nehalem
> +             + __cpu_model.__cpu_is_intel_corei7_westmere
> +             + __cpu_model.__cpu_is_intel_corei7_sandybridge
> +             + __cpu_model.__cpu_is_amdfam10h_barcelona
> +             + __cpu_model.__cpu_is_amdfam10h_shanghai
> +             + __cpu_model.__cpu_is_amdfam10h_istanbul
> +             + __cpu_model.__cpu_is_amdfam15h_bdver1
> +             + __cpu_model.__cpu_is_amdfam15h_bdver2);
> +
> +  gcc_assert (one_type <= 1);
> +  return 0;
> +}
> +
> +/* A noinline function calling __get_cpuid. Having many calls to
> +   cpuid in one function in 32-bit mode causes GCC to complain:
> +   "can’t find a register in class ‘CLOBBERED_REGS’".  This is
> +   related to PR rtl-optimization 44174. */
> +
> +static int __attribute__ ((noinline))
> +__get_cpuid_output (unsigned int __level,
> +                   unsigned int *__eax, unsigned int *__ebx,
> +                   unsigned int *__ecx, unsigned int *__edx)
> +{
> +  return __get_cpuid (__level, __eax, __ebx, __ecx, __edx);
> +}
> +
> +
> +/* A constructor function that is sets __cpu_model and __cpu_features with
> +   the right values.  This needs to run only once.  This constructor is
> +   given the highest priority and it should run before constructors without
> +   the priority set.  However, it still runs after ifunc initializers and
> +   needs to be called explicitly there.  */
> +
> +int __attribute__ ((constructor (101)))
> +__cpu_indicator_init (void)
> +{
> +  unsigned int eax, ebx, ecx, edx;
> +
> +  int max_level = 5;
> +  unsigned int vendor;
> +  unsigned int model, family, brand_id;
> +  unsigned int extended_model, extended_family;
> +  static int called = 0;
> +
> +  /* This function needs to run just once.  */
> +  if (called)
> +    return 0;
> +  else
> +    called = 1;
> +
> +  /* Assume cpuid insn present. Run in level 0 to get vendor id. */
> +  if (!__get_cpuid_output (0, &eax, &ebx, &ecx, &edx))
> +    return -1;
> +
> +  vendor = ebx;
> +  max_level = eax;
> +
> +  if (max_level < 1)
> +    return -1;
> +
> +  if (!__get_cpuid_output (1, &eax, &ebx, &ecx, &edx))
> +    return -1;
> +
> +  model = (eax >> 4) & 0x0f;
> +  family = (eax >> 8) & 0x0f;
> +  brand_id = ebx & 0xff;
> +  extended_model = (eax >> 12) & 0xf0;
> +  extended_family = (eax >> 20) & 0xff;
> +
> +  if (vendor == SIG_INTEL)
> +    {
> +      /* Adjust model and family for Intel CPUS. */
> +      if (family == 0x0f)
> +       {
> +         family += extended_family;
> +         model += extended_model;
> +       }
> +      else if (family == 0x06)
> +       model += extended_model;
> +
> +      /* Get CPU type.  */
> +      __cpu_model.__cpu_is_intel = 1;
> +      get_intel_cpu (family, model, brand_id);
> +    }
> +
> +  if (vendor == SIG_AMD)
> +    {
> +      /* Adjust model and family for AMD CPUS. */
> +      if (family == 0x0f)
> +       {
> +         family += extended_family;
> +         model += (extended_model << 4);
> +       }
> +
> +      /* Get CPU type.  */
> +      __cpu_model.__cpu_is_amd = 1;
> +      get_amd_cpu (family, model);
> +    }
> +
> +  /* Find available features. */
> +  get_available_features (ecx, edx);
> +
> +  sanity_check ();
> +
> +  return 0;
> +}
> Index: libgcc/config/i386/libgcc-glibc.ver
> ===================================================================
> --- libgcc/config/i386/libgcc-glibc.ver (revision 184971)
> +++ libgcc/config/i386/libgcc-glibc.ver (working copy)
> @@ -147,6 +147,11 @@ GCC_4.3.0 {
>   __trunctfxf2
>   __unordtf2
>  }
> +
> +GCC_4.8.0 {
> +  __cpu_model
> +  __cpu_features
> +}
>  %else
>  GCC_4.4.0 {
>   __addtf3
> @@ -183,4 +188,9 @@ GCC_4.4.0 {
>  GCC_4.5.0 {
>   __extendxftf2
>  }
> +
> +GCC_4.8.0 {
> +  __cpu_model
> +  __cpu_features
> +}
>  %endif
> Index: gcc/config/i386/i386-builtin-types.def
> ===================================================================
> --- gcc/config/i386/i386-builtin-types.def      (revision 184971)
> +++ gcc/config/i386/i386-builtin-types.def      (working copy)
> @@ -143,6 +143,7 @@ DEF_FUNCTION_TYPE (UINT64)
>  DEF_FUNCTION_TYPE (UNSIGNED)
>  DEF_FUNCTION_TYPE (VOID)
>  DEF_FUNCTION_TYPE (PVOID)
> +DEF_FUNCTION_TYPE (INT)
>
>  DEF_FUNCTION_TYPE (FLOAT, FLOAT)
>  DEF_FUNCTION_TYPE (FLOAT128, FLOAT128)
> Index: gcc/config/i386/i386.c
> ===================================================================
> --- gcc/config/i386/i386.c      (revision 184971)
> +++ gcc/config/i386/i386.c      (working copy)
> @@ -25637,6 +25637,33 @@ enum ix86_builtins
>   /* CFString built-in for darwin */
>   IX86_BUILTIN_CFSTRING,
>
> +  /* Builtins to get CPU features. */
> +  IX86_BUILTIN_CPU_SUPPORTS_CMOV,
> +  IX86_BUILTIN_CPU_SUPPORTS_MMX,
> +  IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT,
> +  IX86_BUILTIN_CPU_SUPPORTS_SSE,
> +  IX86_BUILTIN_CPU_SUPPORTS_SSE2,
> +  IX86_BUILTIN_CPU_SUPPORTS_SSE3,
> +  IX86_BUILTIN_CPU_SUPPORTS_SSSE3,
> +  IX86_BUILTIN_CPU_SUPPORTS_SSE4_1,
> +  IX86_BUILTIN_CPU_SUPPORTS_SSE4_2,
> +  /* Builtins to get CPU type. */
> +  IX86_BUILTIN_CPU_INIT,
> +  IX86_BUILTIN_CPU_IS_AMD,
> +  IX86_BUILTIN_CPU_IS_INTEL,
> +  IX86_BUILTIN_CPU_IS_INTEL_ATOM,
> +  IX86_BUILTIN_CPU_IS_INTEL_CORE2,
> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7,
> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM,
> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE,
> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE,
> +  IX86_BUILTIN_CPU_IS_AMDFAM10H,
> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA,
> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI,
> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL,
> +  IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1,
> +  IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2,
> +
>   IX86_BUILTIN_MAX
>  };
>
> @@ -27446,6 +27473,593 @@ ix86_init_mmx_sse_builtins (void)
>     }
>  }
>
> +/* Returns a struct type with name NAME and number of fields equal to
> +   NUM_FIELDS.  Each field is a unsigned int bit field of length 1 bit. */
> +
> +static tree
> +build_struct_with_one_bit_fields (int num_fields, const char *name)
> +{
> +  int i;
> +  char field_name [10];
> +  tree field = NULL_TREE, field_chain = NULL_TREE;
> +  tree type = make_node (RECORD_TYPE);
> +
> +  strcpy (field_name, "k_field");
> +
> +  for (i = 0; i < num_fields; i++)
> +    {
> +      /* Name the fields, 0_field, 1_field, ... */
> +      field_name [0] = '0' + i;
> +      field = build_decl (UNKNOWN_LOCATION, FIELD_DECL,
> +                         get_identifier (field_name), unsigned_type_node);
> +      DECL_BIT_FIELD (field) = 1;
> +      DECL_SIZE (field) = bitsize_one_node;
> +      if (field_chain != NULL_TREE)
> +       DECL_CHAIN (field) = field_chain;
> +      field_chain = field;
> +    }
> +  finish_builtin_struct (type, name, field_chain, NULL_TREE);
> +  return type;
> +}
> +
> +/* Returns a extern, comdat VAR_DECL of type TYPE and name NAME. */
> +
> +static tree
> +make_var_decl (tree type, const char *name)
> +{
> +  tree new_decl;
> +  struct varpool_node *vnode;
> +
> +  new_decl = build_decl (UNKNOWN_LOCATION,
> +                        VAR_DECL,
> +                        get_identifier(name),
> +                        type);
> +
> +  DECL_EXTERNAL (new_decl) = 1;
> +  TREE_STATIC (new_decl) = 1;
> +  TREE_PUBLIC (new_decl) = 1;
> +  DECL_INITIAL (new_decl) = 0;
> +  DECL_ARTIFICIAL (new_decl) = 0;
> +  DECL_PRESERVE_P (new_decl) = 1;
> +
> +  make_decl_one_only (new_decl, DECL_ASSEMBLER_NAME (new_decl));
> +  assemble_variable (new_decl, 0, 0, 0);
> +
> +  vnode = varpool_node (new_decl);
> +  gcc_assert (vnode != NULL);
> +  /* Set finalized to 1, otherwise it asserts in function "write_symbol" in
> +     lto-streamer-out.c. */
> +  vnode->finalized = 1;
> +
> +  return new_decl;
> +}
> +
> +/* Traverses the chain of fields in STRUCT_TYPE and returns the FIELD_NUM
> +   numbered field. */
> +
> +static tree
> +get_field_from_struct (tree struct_type, int field_num)
> +{
> +  int i;
> +  tree field = TYPE_FIELDS (struct_type);
> +
> +  for (i = 0; i < field_num; i++, field = DECL_CHAIN(field))
> +    {
> +      gcc_assert (field != NULL_TREE);
> +    }
> +
> +  return field;
> +}
> +
> +/* FNDECL is a __builtin_cpu_* call that is folded into an integer defined
> +   in libgcc/config/i386/i386-cpuinfo.c */
> +
> +static tree
> +fold_builtin_cpu (enum ix86_builtins fn_code)
> +{
> +  /* This is the order of bit-fields in __processor_features in
> +     i386-cpuinfo.c */
> +  enum processor_features
> +  {
> +    F_CMOV = 0,
> +    F_MMX,
> +    F_POPCNT,
> +    F_SSE,
> +    F_SSE2,
> +    F_SSE3,
> +    F_SSSE3,
> +    F_SSE4_1,
> +    F_SSE4_2,
> +    F_MAX
> +  };
> +
> +  /* This is the order of bit-fields in __processor_model in
> +     i386-cpuinfo.c */
> +  enum processor_model
> +  {
> +    M_AMD = 0,
> +    M_INTEL,
> +    M_INTEL_ATOM,
> +    M_INTEL_CORE2,
> +    M_INTEL_COREI7,
> +    M_INTEL_COREI7_NEHALEM,
> +    M_INTEL_COREI7_WESTMERE,
> +    M_INTEL_COREI7_SANDYBRIDGE,
> +    M_AMDFAM10H,
> +    M_AMDFAM10H_BARCELONA,
> +    M_AMDFAM10H_SHANGHAI,
> +    M_AMDFAM10H_ISTANBUL,
> +    M_AMDFAM15H_BDVER1,
> +    M_AMDFAM15H_BDVER2,
> +    M_MAX
> +  };
> +
> +  static tree __processor_features_type = NULL_TREE;
> +  static tree __cpu_features_var = NULL_TREE;
> +  static tree __processor_model_type = NULL_TREE;
> +  static tree __cpu_model_var = NULL_TREE;
> +  static tree field;
> +  static tree which_struct;
> +
> +  if (__processor_features_type == NULL_TREE)
> +    __processor_features_type = build_struct_with_one_bit_fields (F_MAX,
> +                                 "__processor_features");
> +
> +  if (__processor_model_type == NULL_TREE)
> +    __processor_model_type = build_struct_with_one_bit_fields (M_MAX,
> +                                 "__processor_model");
> +
> +  if (__cpu_features_var == NULL_TREE)
> +    __cpu_features_var = make_var_decl (__processor_features_type,
> +                                       "__cpu_features");
> +
> +  if (__cpu_model_var == NULL_TREE)
> +    __cpu_model_var = make_var_decl (__processor_model_type,
> +                                    "__cpu_model");
> +
> +  /* Look at the code to identify the field requested. */
> +  switch (fn_code)
> +    {
> +    case IX86_BUILTIN_CPU_SUPPORTS_CMOV:
> +      field = get_field_from_struct (__processor_features_type, F_CMOV);
> +      which_struct = __cpu_features_var;
> +      break;
> +    case IX86_BUILTIN_CPU_SUPPORTS_MMX:
> +      field = get_field_from_struct (__processor_features_type, F_MMX);
> +      which_struct = __cpu_features_var;
> +      break;
> +    case IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT:
> +      field = get_field_from_struct (__processor_features_type, F_POPCNT);
> +      which_struct = __cpu_features_var;
> +      break;
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE:
> +      field = get_field_from_struct (__processor_features_type, F_SSE);
> +      which_struct = __cpu_features_var;
> +      break;
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE2:
> +      field = get_field_from_struct (__processor_features_type, F_SSE2);
> +      which_struct = __cpu_features_var;
> +      break;
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE3:
> +      field = get_field_from_struct (__processor_features_type, F_SSE3);
> +      which_struct = __cpu_features_var;
> +      break;
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSSE3:
> +      field = get_field_from_struct (__processor_features_type, F_SSSE3);
> +      which_struct = __cpu_features_var;
> +      break;
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_1:
> +      field = get_field_from_struct (__processor_features_type, F_SSE4_1);
> +      which_struct = __cpu_features_var;
> +      break;
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_2:
> +      field = get_field_from_struct (__processor_features_type, F_SSE4_2);
> +      which_struct = __cpu_features_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_AMD:
> +      field = get_field_from_struct (__processor_model_type, M_AMD);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_INTEL:
> +      field = get_field_from_struct (__processor_model_type, M_INTEL);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_INTEL_ATOM:
> +      field = get_field_from_struct (__processor_model_type, M_INTEL_ATOM);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_INTEL_CORE2:
> +      field = get_field_from_struct (__processor_model_type, M_INTEL_CORE2);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_INTEL_COREI7);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_INTEL_COREI7_NEHALEM);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_INTEL_COREI7_WESTMERE);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_INTEL_COREI7_SANDYBRIDGE);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_AMDFAM10H);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_AMDFAM10H_BARCELONA);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_AMDFAM10H_SHANGHAI);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_AMDFAM10H_ISTANBUL);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_AMDFAM15H_BDVER1);
> +      which_struct = __cpu_model_var;
> +      break;
> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2:
> +      field = get_field_from_struct (__processor_model_type,
> +                                    M_AMDFAM15H_BDVER2);
> +      which_struct = __cpu_model_var;
> +      break;
> +    default:
> +      return NULL_TREE;
> +    }
> +
> +  return build3 (COMPONENT_REF, TREE_TYPE (field), which_struct, field, NULL_TREE);
> +}
> +
> +static tree
> +ix86_fold_builtin (tree fndecl, int n_args ATTRIBUTE_UNUSED,
> +                  tree *args ATTRIBUTE_UNUSED, bool ignore ATTRIBUTE_UNUSED)
> +{
> +  const char* decl_name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
> +  if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD
> +      && strstr(decl_name, "__builtin_cpu") != NULL)
> +    {
> +      enum ix86_builtins code = (enum ix86_builtins)
> +                               DECL_FUNCTION_CODE (fndecl);
> +      return fold_builtin_cpu (code);
> +    }
> +  return NULL_TREE;
> +}
> +
> +/* A builtin to init/return the cpu type or feature.  Returns an
> +   integer and the type is a const if IS_CONST is set. */
> +
> +static void
> +make_platform_builtin (const char* name, int code, int is_const)
> +{
> +  tree decl;
> +  tree type;
> +
> +  type = ix86_get_builtin_func_type (INT_FTYPE_VOID);
> +  decl = add_builtin_function (name, type, code, BUILT_IN_MD,
> +                              NULL, NULL_TREE);
> +  gcc_assert (decl != NULL_TREE);
> +  ix86_builtins[(int) code] = decl;
> +  if (is_const)
> +    TREE_READONLY (decl) = 1;
> +}
> +
> +/* Builtins to get CPU type and features supported. */
> +
> +static void
> +ix86_init_platform_type_builtins (void)
> +{
> +  make_platform_builtin ("__builtin_cpu_init",
> +                        IX86_BUILTIN_CPU_INIT, 0);
> +  make_platform_builtin ("__builtin_cpu_supports_cmov",
> +                        IX86_BUILTIN_CPU_SUPPORTS_CMOV, 1);
> +  make_platform_builtin ("__builtin_cpu_supports_mmx",
> +                        IX86_BUILTIN_CPU_SUPPORTS_MMX, 1);
> +  make_platform_builtin ("__builtin_cpu_supports_popcount",
> +                        IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT, 1);
> +  make_platform_builtin ("__builtin_cpu_supports_sse",
> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE, 1);
> +  make_platform_builtin ("__builtin_cpu_supports_sse2",
> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE2, 1);
> +  make_platform_builtin ("__builtin_cpu_supports_sse3",
> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE3, 1);
> +  make_platform_builtin ("__builtin_cpu_supports_ssse3",
> +                        IX86_BUILTIN_CPU_SUPPORTS_SSSE3, 1);
> +  make_platform_builtin ("__builtin_cpu_supports_sse4_1",
> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE4_1, 1);
> +  make_platform_builtin ("__builtin_cpu_supports_sse4_2",
> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE4_2, 1);
> +  make_platform_builtin ("__builtin_cpu_is_amd",
> +                        IX86_BUILTIN_CPU_IS_AMD, 1);
> +  make_platform_builtin ("__builtin_cpu_is_intel_atom",
> +                        IX86_BUILTIN_CPU_IS_INTEL_ATOM, 1);
> +  make_platform_builtin ("__builtin_cpu_is_intel_core2",
> +                        IX86_BUILTIN_CPU_IS_INTEL_CORE2, 1);
> +  make_platform_builtin ("__builtin_cpu_is_intel",
> +                        IX86_BUILTIN_CPU_IS_INTEL, 1);
> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7",
> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7, 1);
> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_nehalem",
> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM, 1);
> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_westmere",
> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE, 1);
> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_sandybridge",
> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE, 1);
> +  make_platform_builtin ("__builtin_cpu_is_amdfam10",
> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H, 1);
> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_barcelona",
> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA, 1);
> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_shanghai",
> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI, 1);
> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_istanbul",
> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL, 1);
> +  make_platform_builtin ("__builtin_cpu_is_amdfam15_bdver1",
> +                        IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1, 1);
> +  make_platform_builtin ("__builtin_cpu_is_amdfam15_bdver2",
> +                        IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2, 1);
> +}
> +
>  /* Internal method for ix86_init_builtins.  */
>
>  static void
> @@ -27529,6 +28143,9 @@ ix86_init_builtins (void)
>
>   ix86_init_builtin_types ();
>
> +  /* Builtins to get CPU type and features. */
> +  ix86_init_platform_type_builtins ();
> +
>   /* TFmode support builtins.  */
>   def_builtin_const (0, "__builtin_infq",
>                     FLOAT128_FTYPE_VOID, IX86_BUILTIN_INFQ);
> @@ -29145,6 +29762,48 @@ ix86_expand_builtin (tree exp, rtx target, rtx sub
>   enum machine_mode mode0, mode1, mode2, mode3, mode4;
>   unsigned int fcode = DECL_FUNCTION_CODE (fndecl);
>
> +  /* For CPU builtins that can be folded, fold first and expand the fold.  */
> +  switch (fcode)
> +    {
> +    case IX86_BUILTIN_CPU_SUPPORTS_CMOV:
> +    case IX86_BUILTIN_CPU_SUPPORTS_MMX:
> +    case IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT:
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE:
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE2:
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE3:
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSSE3:
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_1:
> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_2:
> +    case IX86_BUILTIN_CPU_IS_AMD:
> +    case IX86_BUILTIN_CPU_IS_INTEL:
> +    case IX86_BUILTIN_CPU_IS_INTEL_ATOM:
> +    case IX86_BUILTIN_CPU_IS_INTEL_CORE2:
> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7:
> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM:
> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE:
> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE:
> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H:
> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA:
> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI:
> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL:
> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1:
> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2:
> +      {
> +        tree fold_expr = fold_builtin_cpu ((enum ix86_builtins) fcode);
> +       gcc_assert (fold_expr != NULL_TREE);
> +        return expand_expr (fold_expr, target, mode, EXPAND_NORMAL);
> +      }
> +    case IX86_BUILTIN_CPU_INIT:
> +      {
> +       /* Make it call __cpu_indicator_init in libgcc. */
> +       tree call_expr, fndecl, type;
> +        type = build_function_type_list (integer_type_node, NULL_TREE);
> +       fndecl = build_fn_decl ("__cpu_indicator_init", type);
> +       call_expr = build_call_expr (fndecl, 0);
> +       return expand_expr (call_expr, target, mode, EXPAND_NORMAL);
> +      }
> +    }
> +
>   /* Determine whether the builtin function is available under the current ISA.
>      Originally the builtin was not created if it wasn't applicable to the
>      current ISA based on the command line switches.  With function specific
> @@ -38610,6 +39269,12 @@ ix86_autovectorize_vector_sizes (void)
>  #undef TARGET_BUILD_BUILTIN_VA_LIST
>  #define TARGET_BUILD_BUILTIN_VA_LIST ix86_build_builtin_va_list
>
> +#undef TARGET_FOLD_BUILTIN
> +#define TARGET_FOLD_BUILTIN ix86_fold_builtin
> +
>  #undef TARGET_ENUM_VA_LIST_P
>  #define TARGET_ENUM_VA_LIST_P ix86_enum_va_list
> Index: gcc/testsuite/gcc.target/i386/builtin_target.c
> ===================================================================
> --- gcc/testsuite/gcc.target/i386/builtin_target.c      (revision 0)
> +++ gcc/testsuite/gcc.target/i386/builtin_target.c      (revision 0)
> @@ -0,0 +1,61 @@
> +/* This test checks if the __builtin_cpu_* calls are recognized. */
> +
> +/* { dg-do run } */
> +
> +int
> +fn1 ()
> +{
> +  if (__builtin_cpu_supports_cmov () < 0)
> +    return -1;
> +  if (__builtin_cpu_supports_mmx () < 0)
> +    return -1;
> +  if (__builtin_cpu_supports_popcount () < 0)
> +    return -1;
> +  if (__builtin_cpu_supports_sse () < 0)
> +    return -1;
> +  if (__builtin_cpu_supports_sse2 () < 0)
> +    return -1;
> +  if (__builtin_cpu_supports_sse3 () < 0)
> +    return -1;
> +  if (__builtin_cpu_supports_ssse3 () < 0)
> +    return -1;
> +  if (__builtin_cpu_supports_sse4_1 () < 0)
> +    return -1;
> +  if (__builtin_cpu_supports_sse4_2 () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_amd () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_intel () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_intel_atom () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_intel_core2 () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_intel_corei7 () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_intel_corei7_nehalem () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_intel_corei7_westmere () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_intel_corei7_sandybridge () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_amdfam10 () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_amdfam10_barcelona () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_amdfam10_shanghai () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_amdfam10_istanbul () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_amdfam15_bdver1 () < 0)
> +    return -1;
> +  if (__builtin_cpu_is_amdfam15_bdver2 () < 0)
> +    return -1;
> +
> +  return 0;
> +}
> +
> +int main ()
> +{
> +  return fn1 ();
> +}
>
> --
> This patch is available for review at http://codereview.appspot.com/5754058

On Wed, Mar 7, 2012 at 5:51 AM, Richard Guenther
<richard.guenther@gmail.com> wrote:
> On Wed, Mar 7, 2012 at 1:49 AM, Sriraman Tallam <tmsriram@google.com> wrote:
>> Patch for CPU detection at run-time.
>> ===================================
>>
>> Patch for CPU detection at run-time, to be used in dispatching of
>> multi-versioned functions.   Please see this discussion:
>> http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01355.html
>> when this patch for reviewed the last time.
>>
>> For more detailed description:
>> http://gcc.gnu.org/ml/gcc/2012-03/msg00074.html
>>
>> One of the main concerns was about making CPU detection initialization a
>> constructor. The main point raised was about constructor ordering. I have
>> added a priority value to the CPU detection constructor to make it very high
>> priority so that it is guaranteed to fire before every constructor without
>> an explicitly marked priority value of 101.  However, IFUNC initializers
>> will still fire before this constructor, so the cpu initialization routine
>> has to be explicitly called in such initializers for which I have added a
>> builtin: __builtin_cpu_init ().
>>
>> This patch adds the following new builtins:
>>
>> * __builtin_cpu_init
>> * __builtin_cpu_supports_cmov
>> * __builtin_cpu_supports_mmx
>> * __builtin_cpu_supports_popcount
>> * __builtin_cpu_supports_sse
>> * __builtin_cpu_supports_sse2
>> * __builtin_cpu_supports_sse3
>> * __builtin_cpu_supports_ssse3
>> * __builtin_cpu_supports_sse4_1
>> * __builtin_cpu_supports_sse4_2
>> * __builtin_cpu_is_amd
>> * __builtin_cpu_is_intel_atom
>> * __builtin_cpu_is_intel_core2
>> * __builtin_cpu_is_intel
>> * __builtin_cpu_is_intel_corei7
>> * __builtin_cpu_is_intel_corei7_nehalem
>> * __builtin_cpu_is_intel_corei7_westmere
>> * __builtin_cpu_is_intel_corei7_sandybridge
>> * __builtin_cpu_is_amdfam10
>> * __builtin_cpu_is_amdfam10_barcelona
>> * __builtin_cpu_is_amdfam10_shanghai
>> * __builtin_cpu_is_amdfam10_istanbul
>> * __builtin_cpu_is_amdfam15_bdver1
>> * __builtin_cpu_is_amdfam15_bdver2
>
> I think the non-feature detection functions are not necessary at all.

They are useful if compiler needs to do auto versioning based on cpu model.

> Builtin functions are not exactly cheap, nor is the scheme you invent
> backward/forward compatible.  Instead, why not add a single builtin
> function, __builtin_cpu_supports(const char *), and decode from
> a comma-separated list of features?  Unknown features are simply
> "not present".  So I can write code with only a single configure check,

This is a good idea.

__builtin_is_cpu (const char* );
__builtin_cpu_supports (char char*);

thanks,

David


> for __builtin_cpu_supports, and cater for future features or older compilers.
>
> And of course that builtin would be even cross-platform.
>
> Implementation-wise I'll leave this to x86 maintainers to comment on.
>
> Richard.
>
>>
>>        * config/i386/i386.c (build_struct_with_one_bit_fields): New function.
>>        (make_var_decl): New function.
>>        (get_field_from_struct): New function.
>>        (fold_builtin_target): New function.
>>        (ix86_fold_builtin): New function.
>>        (ix86_expand_builtin): Expand new builtins by folding them.
>>        (make_platform_builtin): New functions.
>>        (ix86_init_platform_type_builtins): Make the new builtins.
>>        (ix86_init_builtins): Make new builtins to detect CPU type.
>>        (TARGET_FOLD_BUILTIN): New macro.
>>        (IX86_BUILTIN_CPU_SUPPORTS_CMOV): New enum value.
>>        (IX86_BUILTIN_CPU_SUPPORTS_MMX): New enum value.
>>        (IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT): New enum value.
>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE): New enum value.
>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE2): New enum value.
>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE3): New enum value.
>>        (IX86_BUILTIN_CPU_SUPPORTS_SSSE3): New enum value.
>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_1): New enum value.
>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_2): New enum value.
>>        (IX86_BUILTIN_CPU_INIT): New enum value.
>>        (IX86_BUILTIN_CPU_IS_AMD): New enum value.
>>        (IX86_BUILTIN_CPU_IS_INTEL): New enum value.
>>        (IX86_BUILTIN_CPU_IS_INTEL_ATOM): New enum value.
>>        (IX86_BUILTIN_CPU_IS_INTEL_CORE2): New enum value.
>>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM): New enum value.
>>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE): New enum value.
>>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE): New enum value.
>>        (IX86_BUILTIN_CPU_IS_AMDFAM10_BARCELONA): New enum value.
>>        (IX86_BUILTIN_CPU_IS_AMDFAM10_SHANGHAI): New enum value.
>>        (IX86_BUILTIN_CPU_IS_AMDFAM10_ISTANBUL): New enum value.
>>        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1): New enum value.
>>        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2): New enum value.
>>        * config/i386/i386-builtin-types.def: New function type.
>>        * testsuite/gcc.target/builtin_target.c: New testcase.
>>
>>        * libgcc/config/i386/i386-cpuinfo.c: New file.
>>        * libgcc/config/i386/t-cpuinfo: New file.
>>        * libgcc/config.host: Include t-cpuinfo.
>>        * libgcc/config/i386/libgcc-glibc.ver: Version symbols __cpu_model
>>        and __cpu_features.
>>
>> Index: libgcc/config.host
>> ===================================================================
>> --- libgcc/config.host  (revision 184971)
>> +++ libgcc/config.host  (working copy)
>> @@ -1142,7 +1142,7 @@ i[34567]86-*-linux* | x86_64-*-linux* | \
>>   i[34567]86-*-kfreebsd*-gnu | x86_64-*-kfreebsd*-gnu | \
>>   i[34567]86-*-knetbsd*-gnu | \
>>   i[34567]86-*-gnu*)
>> -       tmake_file="${tmake_file} t-tls i386/t-linux"
>> +       tmake_file="${tmake_file} t-tls i386/t-linux i386/t-cpuinfo"
>>        if test "$libgcc_cv_cfi" = "yes"; then
>>                tmake_file="${tmake_file} t-stack i386/t-stack-i386"
>>        fi
>> Index: libgcc/config/i386/t-cpuinfo
>> ===================================================================
>> --- libgcc/config/i386/t-cpuinfo        (revision 0)
>> +++ libgcc/config/i386/t-cpuinfo        (revision 0)
>> @@ -0,0 +1 @@
>> +LIB2ADD += $(srcdir)/config/i386/i386-cpuinfo.c
>> Index: libgcc/config/i386/i386-cpuinfo.c
>> ===================================================================
>> --- libgcc/config/i386/i386-cpuinfo.c   (revision 0)
>> +++ libgcc/config/i386/i386-cpuinfo.c   (revision 0)
>> @@ -0,0 +1,306 @@
>> +/* Get CPU type and Features for x86 processors.
>> +   Copyright (C) 2011 Free Software Foundation, Inc.
>> +   Contributed by Sriraman Tallam (tmsriram@google.com)
>> +
>> +This file is part of GCC.
>> +
>> +GCC is free software; you can redistribute it and/or modify it under
>> +the terms of the GNU General Public License as published by the Free
>> +Software Foundation; either version 3, or (at your option) any later
>> +version.
>> +
>> +GCC is distributed in the hope that it will be useful, but WITHOUT ANY
>> +WARRANTY; without even the implied warranty of MERCHANTABILITY or
>> +FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
>> +for more details.
>> +
>> +You should have received a copy of the GNU General Public License
>> +along with GCC; see the file COPYING3.  If not see
>> +<http://www.gnu.org/licenses/>. */
>> +
>> +#include "cpuid.h"
>> +#include "tsystem.h"
>> +
>> +int __cpu_indicator_init (void) __attribute__ ((constructor (101)));
>> +
>> +enum vendor_signatures
>> +{
>> +  SIG_INTEL =  0x756e6547 /* Genu */,
>> +  SIG_AMD =    0x68747541 /* Auth */
>> +};
>> +
>> +/* ISA Features supported. */
>> +
>> +struct __processor_features
>> +{
>> +  unsigned int __cpu_cmov : 1;
>> +  unsigned int __cpu_mmx : 1;
>> +  unsigned int __cpu_popcnt : 1;
>> +  unsigned int __cpu_sse : 1;
>> +  unsigned int __cpu_sse2 : 1;
>> +  unsigned int __cpu_sse3 : 1;
>> +  unsigned int __cpu_ssse3 : 1;
>> +  unsigned int __cpu_sse4_1 : 1;
>> +  unsigned int __cpu_sse4_2 : 1;
>> +} __cpu_features;
>> +
>> +/* Processor Model. */
>> +
>> +struct __processor_model
>> +{
>> +  /* Vendor. */
>> +  unsigned int __cpu_is_amd : 1;
>> +  unsigned int __cpu_is_intel : 1;
>> +  /* CPU type. */
>> +  unsigned int __cpu_is_intel_atom : 1;
>> +  unsigned int __cpu_is_intel_core2 : 1;
>> +  unsigned int __cpu_is_intel_corei7 : 1;
>> +  unsigned int __cpu_is_intel_corei7_nehalem : 1;
>> +  unsigned int __cpu_is_intel_corei7_westmere : 1;
>> +  unsigned int __cpu_is_intel_corei7_sandybridge : 1;
>> +  unsigned int __cpu_is_amdfam10h : 1;
>> +  unsigned int __cpu_is_amdfam10h_barcelona : 1;
>> +  unsigned int __cpu_is_amdfam10h_shanghai : 1;
>> +  unsigned int __cpu_is_amdfam10h_istanbul : 1;
>> +  unsigned int __cpu_is_amdfam15h_bdver1 : 1;
>> +  unsigned int __cpu_is_amdfam15h_bdver2 : 1;
>> +} __cpu_model;
>> +
>> +/* Get the specific type of AMD CPU.  */
>> +
>> +static void
>> +get_amd_cpu (unsigned int family, unsigned int model)
>> +{
>> +  switch (family)
>> +    {
>> +    /* AMD Family 10h.  */
>> +    case 0x10:
>> +      switch (model)
>> +       {
>> +       case 0x2:
>> +         /* Barcelona.  */
>> +         __cpu_model.__cpu_is_amdfam10h = 1;
>> +         __cpu_model.__cpu_is_amdfam10h_barcelona = 1;
>> +         break;
>> +       case 0x4:
>> +         /* Shanghai.  */
>> +         __cpu_model.__cpu_is_amdfam10h = 1;
>> +         __cpu_model.__cpu_is_amdfam10h_shanghai = 1;
>> +         break;
>> +       case 0x8:
>> +         /* Istanbul.  */
>> +         __cpu_model.__cpu_is_amdfam10h = 1;
>> +         __cpu_model.__cpu_is_amdfam10h_istanbul = 1;
>> +         break;
>> +       default:
>> +         break;
>> +       }
>> +      break;
>> +    /* AMD Family 15h.  */
>> +    case 0x15:
>> +      /* Bulldozer version 1.  */
>> +      if (model >= 0 && model <= 0xf)
>> +        __cpu_model.__cpu_is_amdfam15h_bdver1 = 1;
>> +      /* Bulldozer version 2.  */
>> +      if (model >= 0x10 && model <= 0x1f)
>> +        __cpu_model.__cpu_is_amdfam15h_bdver2 = 1;
>> +      break;
>> +    default:
>> +      break;
>> +    }
>> +}
>> +
>> +/* Get the specific type of Intel CPU.  */
>> +
>> +static void
>> +get_intel_cpu (unsigned int family, unsigned int model, unsigned int brand_id)
>> +{
>> +  /* Parse family and model only if brand ID is 0. */
>> +  if (brand_id == 0)
>> +    {
>> +      switch (family)
>> +       {
>> +       case 0x5:
>> +         /* Pentium.  */
>> +         break;
>> +       case 0x6:
>> +         switch (model)
>> +           {
>> +           case 0x1c:
>> +           case 0x26:
>> +             /* Atom.  */
>> +             __cpu_model.__cpu_is_intel_atom = 1;
>> +             break;
>> +           case 0x1a:
>> +           case 0x1e:
>> +           case 0x1f:
>> +           case 0x2e:
>> +             /* Nehalem.  */
>> +             __cpu_model.__cpu_is_intel_corei7 = 1;
>> +             __cpu_model.__cpu_is_intel_corei7_nehalem = 1;
>> +             break;
>> +           case 0x25:
>> +           case 0x2c:
>> +           case 0x2f:
>> +             /* Westmere.  */
>> +             __cpu_model.__cpu_is_intel_corei7 = 1;
>> +             __cpu_model.__cpu_is_intel_corei7_westmere = 1;
>> +             break;
>> +           case 0x2a:
>> +             /* Sandy Bridge.  */
>> +             __cpu_model.__cpu_is_intel_corei7 = 1;
>> +             __cpu_model.__cpu_is_intel_corei7_sandybridge = 1;
>> +             break;
>> +           case 0x17:
>> +           case 0x1d:
>> +             /* Penryn.  */
>> +           case 0x0f:
>> +             /* Merom.  */
>> +             __cpu_model.__cpu_is_intel_core2 = 1;
>> +             break;
>> +           default:
>> +             break;
>> +           }
>> +         break;
>> +       default:
>> +         /* We have no idea.  */
>> +         break;
>> +       }
>> +    }
>> +}
>> +
>> +static void
>> +get_available_features (unsigned int ecx, unsigned int edx)
>> +{
>> +  __cpu_features.__cpu_cmov = (edx & bit_CMOV) ? 1 : 0;
>> +  __cpu_features.__cpu_mmx = (edx & bit_MMX) ? 1 : 0;
>> +  __cpu_features.__cpu_sse = (edx & bit_SSE) ? 1 : 0;
>> +  __cpu_features.__cpu_sse2 = (edx & bit_SSE2) ? 1 : 0;
>> +  __cpu_features.__cpu_popcnt = (ecx & bit_POPCNT) ? 1 : 0;
>> +  __cpu_features.__cpu_sse3 = (ecx & bit_SSE3) ? 1 : 0;
>> +  __cpu_features.__cpu_ssse3 = (ecx & bit_SSSE3) ? 1 : 0;
>> +  __cpu_features.__cpu_sse4_1 = (ecx & bit_SSE4_1) ? 1 : 0;
>> +  __cpu_features.__cpu_sse4_2 = (ecx & bit_SSE4_2) ? 1 : 0;
>> +}
>> +
>> +
>> +/* Sanity check for the vendor and cpu type flags.  */
>> +
>> +static int
>> +sanity_check (void)
>> +{
>> +  unsigned int one_type = 0;
>> +
>> +  /* Vendor cannot be Intel and AMD. */
>> +  gcc_assert((__cpu_model.__cpu_is_intel == 0)
>> +             || (__cpu_model.__cpu_is_amd == 0));
>> +
>> +  /* Only one CPU type can be set. */
>> +  one_type = (__cpu_model.__cpu_is_intel_atom
>> +             + __cpu_model.__cpu_is_intel_core2
>> +             + __cpu_model.__cpu_is_intel_corei7_nehalem
>> +             + __cpu_model.__cpu_is_intel_corei7_westmere
>> +             + __cpu_model.__cpu_is_intel_corei7_sandybridge
>> +             + __cpu_model.__cpu_is_amdfam10h_barcelona
>> +             + __cpu_model.__cpu_is_amdfam10h_shanghai
>> +             + __cpu_model.__cpu_is_amdfam10h_istanbul
>> +             + __cpu_model.__cpu_is_amdfam15h_bdver1
>> +             + __cpu_model.__cpu_is_amdfam15h_bdver2);
>> +
>> +  gcc_assert (one_type <= 1);
>> +  return 0;
>> +}
>> +
>> +/* A noinline function calling __get_cpuid. Having many calls to
>> +   cpuid in one function in 32-bit mode causes GCC to complain:
>> +   "can’t find a register in class ‘CLOBBERED_REGS’".  This is
>> +   related to PR rtl-optimization 44174. */
>> +
>> +static int __attribute__ ((noinline))
>> +__get_cpuid_output (unsigned int __level,
>> +                   unsigned int *__eax, unsigned int *__ebx,
>> +                   unsigned int *__ecx, unsigned int *__edx)
>> +{
>> +  return __get_cpuid (__level, __eax, __ebx, __ecx, __edx);
>> +}
>> +
>> +
>> +/* A constructor function that is sets __cpu_model and __cpu_features with
>> +   the right values.  This needs to run only once.  This constructor is
>> +   given the highest priority and it should run before constructors without
>> +   the priority set.  However, it still runs after ifunc initializers and
>> +   needs to be called explicitly there.  */
>> +
>> +int __attribute__ ((constructor (101)))
>> +__cpu_indicator_init (void)
>> +{
>> +  unsigned int eax, ebx, ecx, edx;
>> +
>> +  int max_level = 5;
>> +  unsigned int vendor;
>> +  unsigned int model, family, brand_id;
>> +  unsigned int extended_model, extended_family;
>> +  static int called = 0;
>> +
>> +  /* This function needs to run just once.  */
>> +  if (called)
>> +    return 0;
>> +  else
>> +    called = 1;
>> +
>> +  /* Assume cpuid insn present. Run in level 0 to get vendor id. */
>> +  if (!__get_cpuid_output (0, &eax, &ebx, &ecx, &edx))
>> +    return -1;
>> +
>> +  vendor = ebx;
>> +  max_level = eax;
>> +
>> +  if (max_level < 1)
>> +    return -1;
>> +
>> +  if (!__get_cpuid_output (1, &eax, &ebx, &ecx, &edx))
>> +    return -1;
>> +
>> +  model = (eax >> 4) & 0x0f;
>> +  family = (eax >> 8) & 0x0f;
>> +  brand_id = ebx & 0xff;
>> +  extended_model = (eax >> 12) & 0xf0;
>> +  extended_family = (eax >> 20) & 0xff;
>> +
>> +  if (vendor == SIG_INTEL)
>> +    {
>> +      /* Adjust model and family for Intel CPUS. */
>> +      if (family == 0x0f)
>> +       {
>> +         family += extended_family;
>> +         model += extended_model;
>> +       }
>> +      else if (family == 0x06)
>> +       model += extended_model;
>> +
>> +      /* Get CPU type.  */
>> +      __cpu_model.__cpu_is_intel = 1;
>> +      get_intel_cpu (family, model, brand_id);
>> +    }
>> +
>> +  if (vendor == SIG_AMD)
>> +    {
>> +      /* Adjust model and family for AMD CPUS. */
>> +      if (family == 0x0f)
>> +       {
>> +         family += extended_family;
>> +         model += (extended_model << 4);
>> +       }
>> +
>> +      /* Get CPU type.  */
>> +      __cpu_model.__cpu_is_amd = 1;
>> +      get_amd_cpu (family, model);
>> +    }
>> +
>> +  /* Find available features. */
>> +  get_available_features (ecx, edx);
>> +
>> +  sanity_check ();
>> +
>> +  return 0;
>> +}
>> Index: libgcc/config/i386/libgcc-glibc.ver
>> ===================================================================
>> --- libgcc/config/i386/libgcc-glibc.ver (revision 184971)
>> +++ libgcc/config/i386/libgcc-glibc.ver (working copy)
>> @@ -147,6 +147,11 @@ GCC_4.3.0 {
>>   __trunctfxf2
>>   __unordtf2
>>  }
>> +
>> +GCC_4.8.0 {
>> +  __cpu_model
>> +  __cpu_features
>> +}
>>  %else
>>  GCC_4.4.0 {
>>   __addtf3
>> @@ -183,4 +188,9 @@ GCC_4.4.0 {
>>  GCC_4.5.0 {
>>   __extendxftf2
>>  }
>> +
>> +GCC_4.8.0 {
>> +  __cpu_model
>> +  __cpu_features
>> +}
>>  %endif
>> Index: gcc/config/i386/i386-builtin-types.def
>> ===================================================================
>> --- gcc/config/i386/i386-builtin-types.def      (revision 184971)
>> +++ gcc/config/i386/i386-builtin-types.def      (working copy)
>> @@ -143,6 +143,7 @@ DEF_FUNCTION_TYPE (UINT64)
>>  DEF_FUNCTION_TYPE (UNSIGNED)
>>  DEF_FUNCTION_TYPE (VOID)
>>  DEF_FUNCTION_TYPE (PVOID)
>> +DEF_FUNCTION_TYPE (INT)
>>
>>  DEF_FUNCTION_TYPE (FLOAT, FLOAT)
>>  DEF_FUNCTION_TYPE (FLOAT128, FLOAT128)
>> Index: gcc/config/i386/i386.c
>> ===================================================================
>> --- gcc/config/i386/i386.c      (revision 184971)
>> +++ gcc/config/i386/i386.c      (working copy)
>> @@ -25637,6 +25637,33 @@ enum ix86_builtins
>>   /* CFString built-in for darwin */
>>   IX86_BUILTIN_CFSTRING,
>>
>> +  /* Builtins to get CPU features. */
>> +  IX86_BUILTIN_CPU_SUPPORTS_CMOV,
>> +  IX86_BUILTIN_CPU_SUPPORTS_MMX,
>> +  IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT,
>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE,
>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE2,
>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE3,
>> +  IX86_BUILTIN_CPU_SUPPORTS_SSSE3,
>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE4_1,
>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE4_2,
>> +  /* Builtins to get CPU type. */
>> +  IX86_BUILTIN_CPU_INIT,
>> +  IX86_BUILTIN_CPU_IS_AMD,
>> +  IX86_BUILTIN_CPU_IS_INTEL,
>> +  IX86_BUILTIN_CPU_IS_INTEL_ATOM,
>> +  IX86_BUILTIN_CPU_IS_INTEL_CORE2,
>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7,
>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM,
>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE,
>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE,
>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H,
>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA,
>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI,
>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL,
>> +  IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1,
>> +  IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2,
>> +
>>   IX86_BUILTIN_MAX
>>  };
>>
>> @@ -27446,6 +27473,593 @@ ix86_init_mmx_sse_builtins (void)
>>     }
>>  }
>>
>> +/* Returns a struct type with name NAME and number of fields equal to
>> +   NUM_FIELDS.  Each field is a unsigned int bit field of length 1 bit. */
>> +
>> +static tree
>> +build_struct_with_one_bit_fields (int num_fields, const char *name)
>> +{
>> +  int i;
>> +  char field_name [10];
>> +  tree field = NULL_TREE, field_chain = NULL_TREE;
>> +  tree type = make_node (RECORD_TYPE);
>> +
>> +  strcpy (field_name, "k_field");
>> +
>> +  for (i = 0; i < num_fields; i++)
>> +    {
>> +      /* Name the fields, 0_field, 1_field, ... */
>> +      field_name [0] = '0' + i;
>> +      field = build_decl (UNKNOWN_LOCATION, FIELD_DECL,
>> +                         get_identifier (field_name), unsigned_type_node);
>> +      DECL_BIT_FIELD (field) = 1;
>> +      DECL_SIZE (field) = bitsize_one_node;
>> +      if (field_chain != NULL_TREE)
>> +       DECL_CHAIN (field) = field_chain;
>> +      field_chain = field;
>> +    }
>> +  finish_builtin_struct (type, name, field_chain, NULL_TREE);
>> +  return type;
>> +}
>> +
>> +/* Returns a extern, comdat VAR_DECL of type TYPE and name NAME. */
>> +
>> +static tree
>> +make_var_decl (tree type, const char *name)
>> +{
>> +  tree new_decl;
>> +  struct varpool_node *vnode;
>> +
>> +  new_decl = build_decl (UNKNOWN_LOCATION,
>> +                        VAR_DECL,
>> +                        get_identifier(name),
>> +                        type);
>> +
>> +  DECL_EXTERNAL (new_decl) = 1;
>> +  TREE_STATIC (new_decl) = 1;
>> +  TREE_PUBLIC (new_decl) = 1;
>> +  DECL_INITIAL (new_decl) = 0;
>> +  DECL_ARTIFICIAL (new_decl) = 0;
>> +  DECL_PRESERVE_P (new_decl) = 1;
>> +
>> +  make_decl_one_only (new_decl, DECL_ASSEMBLER_NAME (new_decl));
>> +  assemble_variable (new_decl, 0, 0, 0);
>> +
>> +  vnode = varpool_node (new_decl);
>> +  gcc_assert (vnode != NULL);
>> +  /* Set finalized to 1, otherwise it asserts in function "write_symbol" in
>> +     lto-streamer-out.c. */
>> +  vnode->finalized = 1;
>> +
>> +  return new_decl;
>> +}
>> +
>> +/* Traverses the chain of fields in STRUCT_TYPE and returns the FIELD_NUM
>> +   numbered field. */
>> +
>> +static tree
>> +get_field_from_struct (tree struct_type, int field_num)
>> +{
>> +  int i;
>> +  tree field = TYPE_FIELDS (struct_type);
>> +
>> +  for (i = 0; i < field_num; i++, field = DECL_CHAIN(field))
>> +    {
>> +      gcc_assert (field != NULL_TREE);
>> +    }
>> +
>> +  return field;
>> +}
>> +
>> +/* FNDECL is a __builtin_cpu_* call that is folded into an integer defined
>> +   in libgcc/config/i386/i386-cpuinfo.c */
>> +
>> +static tree
>> +fold_builtin_cpu (enum ix86_builtins fn_code)
>> +{
>> +  /* This is the order of bit-fields in __processor_features in
>> +     i386-cpuinfo.c */
>> +  enum processor_features
>> +  {
>> +    F_CMOV = 0,
>> +    F_MMX,
>> +    F_POPCNT,
>> +    F_SSE,
>> +    F_SSE2,
>> +    F_SSE3,
>> +    F_SSSE3,
>> +    F_SSE4_1,
>> +    F_SSE4_2,
>> +    F_MAX
>> +  };
>> +
>> +  /* This is the order of bit-fields in __processor_model in
>> +     i386-cpuinfo.c */
>> +  enum processor_model
>> +  {
>> +    M_AMD = 0,
>> +    M_INTEL,
>> +    M_INTEL_ATOM,
>> +    M_INTEL_CORE2,
>> +    M_INTEL_COREI7,
>> +    M_INTEL_COREI7_NEHALEM,
>> +    M_INTEL_COREI7_WESTMERE,
>> +    M_INTEL_COREI7_SANDYBRIDGE,
>> +    M_AMDFAM10H,
>> +    M_AMDFAM10H_BARCELONA,
>> +    M_AMDFAM10H_SHANGHAI,
>> +    M_AMDFAM10H_ISTANBUL,
>> +    M_AMDFAM15H_BDVER1,
>> +    M_AMDFAM15H_BDVER2,
>> +    M_MAX
>> +  };
>> +
>> +  static tree __processor_features_type = NULL_TREE;
>> +  static tree __cpu_features_var = NULL_TREE;
>> +  static tree __processor_model_type = NULL_TREE;
>> +  static tree __cpu_model_var = NULL_TREE;
>> +  static tree field;
>> +  static tree which_struct;
>> +
>> +  if (__processor_features_type == NULL_TREE)
>> +    __processor_features_type = build_struct_with_one_bit_fields (F_MAX,
>> +                                 "__processor_features");
>> +
>> +  if (__processor_model_type == NULL_TREE)
>> +    __processor_model_type = build_struct_with_one_bit_fields (M_MAX,
>> +                                 "__processor_model");
>> +
>> +  if (__cpu_features_var == NULL_TREE)
>> +    __cpu_features_var = make_var_decl (__processor_features_type,
>> +                                       "__cpu_features");
>> +
>> +  if (__cpu_model_var == NULL_TREE)
>> +    __cpu_model_var = make_var_decl (__processor_model_type,
>> +                                    "__cpu_model");
>> +
>> +  /* Look at the code to identify the field requested. */
>> +  switch (fn_code)
>> +    {
>> +    case IX86_BUILTIN_CPU_SUPPORTS_CMOV:
>> +      field = get_field_from_struct (__processor_features_type, F_CMOV);
>> +      which_struct = __cpu_features_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_SUPPORTS_MMX:
>> +      field = get_field_from_struct (__processor_features_type, F_MMX);
>> +      which_struct = __cpu_features_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT:
>> +      field = get_field_from_struct (__processor_features_type, F_POPCNT);
>> +      which_struct = __cpu_features_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE:
>> +      field = get_field_from_struct (__processor_features_type, F_SSE);
>> +      which_struct = __cpu_features_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE2:
>> +      field = get_field_from_struct (__processor_features_type, F_SSE2);
>> +      which_struct = __cpu_features_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE3:
>> +      field = get_field_from_struct (__processor_features_type, F_SSE3);
>> +      which_struct = __cpu_features_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSSE3:
>> +      field = get_field_from_struct (__processor_features_type, F_SSSE3);
>> +      which_struct = __cpu_features_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_1:
>> +      field = get_field_from_struct (__processor_features_type, F_SSE4_1);
>> +      which_struct = __cpu_features_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_2:
>> +      field = get_field_from_struct (__processor_features_type, F_SSE4_2);
>> +      which_struct = __cpu_features_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_AMD:
>> +      field = get_field_from_struct (__processor_model_type, M_AMD);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_INTEL:
>> +      field = get_field_from_struct (__processor_model_type, M_INTEL);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_INTEL_ATOM:
>> +      field = get_field_from_struct (__processor_model_type, M_INTEL_ATOM);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_INTEL_CORE2:
>> +      field = get_field_from_struct (__processor_model_type, M_INTEL_CORE2);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_INTEL_COREI7);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_INTEL_COREI7_NEHALEM);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_INTEL_COREI7_WESTMERE);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_INTEL_COREI7_SANDYBRIDGE);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_AMDFAM10H);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_AMDFAM10H_BARCELONA);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_AMDFAM10H_SHANGHAI);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_AMDFAM10H_ISTANBUL);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_AMDFAM15H_BDVER1);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2:
>> +      field = get_field_from_struct (__processor_model_type,
>> +                                    M_AMDFAM15H_BDVER2);
>> +      which_struct = __cpu_model_var;
>> +      break;
>> +    default:
>> +      return NULL_TREE;
>> +    }
>> +
>> +  return build3 (COMPONENT_REF, TREE_TYPE (field), which_struct, field, NULL_TREE);
>> +}
>> +
>> +static tree
>> +ix86_fold_builtin (tree fndecl, int n_args ATTRIBUTE_UNUSED,
>> +                  tree *args ATTRIBUTE_UNUSED, bool ignore ATTRIBUTE_UNUSED)
>> +{
>> +  const char* decl_name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
>> +  if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD
>> +      && strstr(decl_name, "__builtin_cpu") != NULL)
>> +    {
>> +      enum ix86_builtins code = (enum ix86_builtins)
>> +                               DECL_FUNCTION_CODE (fndecl);
>> +      return fold_builtin_cpu (code);
>> +    }
>> +  return NULL_TREE;
>> +}
>> +
>> +/* A builtin to init/return the cpu type or feature.  Returns an
>> +   integer and the type is a const if IS_CONST is set. */
>> +
>> +static void
>> +make_platform_builtin (const char* name, int code, int is_const)
>> +{
>> +  tree decl;
>> +  tree type;
>> +
>> +  type = ix86_get_builtin_func_type (INT_FTYPE_VOID);
>> +  decl = add_builtin_function (name, type, code, BUILT_IN_MD,
>> +                              NULL, NULL_TREE);
>> +  gcc_assert (decl != NULL_TREE);
>> +  ix86_builtins[(int) code] = decl;
>> +  if (is_const)
>> +    TREE_READONLY (decl) = 1;
>> +}
>> +
>> +/* Builtins to get CPU type and features supported. */
>> +
>> +static void
>> +ix86_init_platform_type_builtins (void)
>> +{
>> +  make_platform_builtin ("__builtin_cpu_init",
>> +                        IX86_BUILTIN_CPU_INIT, 0);
>> +  make_platform_builtin ("__builtin_cpu_supports_cmov",
>> +                        IX86_BUILTIN_CPU_SUPPORTS_CMOV, 1);
>> +  make_platform_builtin ("__builtin_cpu_supports_mmx",
>> +                        IX86_BUILTIN_CPU_SUPPORTS_MMX, 1);
>> +  make_platform_builtin ("__builtin_cpu_supports_popcount",
>> +                        IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT, 1);
>> +  make_platform_builtin ("__builtin_cpu_supports_sse",
>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE, 1);
>> +  make_platform_builtin ("__builtin_cpu_supports_sse2",
>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE2, 1);
>> +  make_platform_builtin ("__builtin_cpu_supports_sse3",
>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE3, 1);
>> +  make_platform_builtin ("__builtin_cpu_supports_ssse3",
>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSSE3, 1);
>> +  make_platform_builtin ("__builtin_cpu_supports_sse4_1",
>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE4_1, 1);
>> +  make_platform_builtin ("__builtin_cpu_supports_sse4_2",
>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE4_2, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_amd",
>> +                        IX86_BUILTIN_CPU_IS_AMD, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_intel_atom",
>> +                        IX86_BUILTIN_CPU_IS_INTEL_ATOM, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_intel_core2",
>> +                        IX86_BUILTIN_CPU_IS_INTEL_CORE2, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_intel",
>> +                        IX86_BUILTIN_CPU_IS_INTEL, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7",
>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_nehalem",
>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_westmere",
>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_sandybridge",
>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10",
>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_barcelona",
>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_shanghai",
>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_istanbul",
>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_amdfam15_bdver1",
>> +                        IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1, 1);
>> +  make_platform_builtin ("__builtin_cpu_is_amdfam15_bdver2",
>> +                        IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2, 1);
>> +}
>> +
>>  /* Internal method for ix86_init_builtins.  */
>>
>>  static void
>> @@ -27529,6 +28143,9 @@ ix86_init_builtins (void)
>>
>>   ix86_init_builtin_types ();
>>
>> +  /* Builtins to get CPU type and features. */
>> +  ix86_init_platform_type_builtins ();
>> +
>>   /* TFmode support builtins.  */
>>   def_builtin_const (0, "__builtin_infq",
>>                     FLOAT128_FTYPE_VOID, IX86_BUILTIN_INFQ);
>> @@ -29145,6 +29762,48 @@ ix86_expand_builtin (tree exp, rtx target, rtx sub
>>   enum machine_mode mode0, mode1, mode2, mode3, mode4;
>>   unsigned int fcode = DECL_FUNCTION_CODE (fndecl);
>>
>> +  /* For CPU builtins that can be folded, fold first and expand the fold.  */
>> +  switch (fcode)
>> +    {
>> +    case IX86_BUILTIN_CPU_SUPPORTS_CMOV:
>> +    case IX86_BUILTIN_CPU_SUPPORTS_MMX:
>> +    case IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT:
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE:
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE2:
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE3:
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSSE3:
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_1:
>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_2:
>> +    case IX86_BUILTIN_CPU_IS_AMD:
>> +    case IX86_BUILTIN_CPU_IS_INTEL:
>> +    case IX86_BUILTIN_CPU_IS_INTEL_ATOM:
>> +    case IX86_BUILTIN_CPU_IS_INTEL_CORE2:
>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7:
>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM:
>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE:
>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE:
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H:
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA:
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI:
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL:
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1:
>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2:
>> +      {
>> +        tree fold_expr = fold_builtin_cpu ((enum ix86_builtins) fcode);
>> +       gcc_assert (fold_expr != NULL_TREE);
>> +        return expand_expr (fold_expr, target, mode, EXPAND_NORMAL);
>> +      }
>> +    case IX86_BUILTIN_CPU_INIT:
>> +      {
>> +       /* Make it call __cpu_indicator_init in libgcc. */
>> +       tree call_expr, fndecl, type;
>> +        type = build_function_type_list (integer_type_node, NULL_TREE);
>> +       fndecl = build_fn_decl ("__cpu_indicator_init", type);
>> +       call_expr = build_call_expr (fndecl, 0);
>> +       return expand_expr (call_expr, target, mode, EXPAND_NORMAL);
>> +      }
>> +    }
>> +
>>   /* Determine whether the builtin function is available under the current ISA.
>>      Originally the builtin was not created if it wasn't applicable to the
>>      current ISA based on the command line switches.  With function specific
>> @@ -38610,6 +39269,12 @@ ix86_autovectorize_vector_sizes (void)
>>  #undef TARGET_BUILD_BUILTIN_VA_LIST
>>  #define TARGET_BUILD_BUILTIN_VA_LIST ix86_build_builtin_va_list
>>
>> +#undef TARGET_FOLD_BUILTIN
>> +#define TARGET_FOLD_BUILTIN ix86_fold_builtin
>> +
>>  #undef TARGET_ENUM_VA_LIST_P
>>  #define TARGET_ENUM_VA_LIST_P ix86_enum_va_list
>> Index: gcc/testsuite/gcc.target/i386/builtin_target.c
>> ===================================================================
>> --- gcc/testsuite/gcc.target/i386/builtin_target.c      (revision 0)
>> +++ gcc/testsuite/gcc.target/i386/builtin_target.c      (revision 0)
>> @@ -0,0 +1,61 @@
>> +/* This test checks if the __builtin_cpu_* calls are recognized. */
>> +
>> +/* { dg-do run } */
>> +
>> +int
>> +fn1 ()
>> +{
>> +  if (__builtin_cpu_supports_cmov () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_supports_mmx () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_supports_popcount () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_supports_sse () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_supports_sse2 () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_supports_sse3 () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_supports_ssse3 () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_supports_sse4_1 () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_supports_sse4_2 () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_amd () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_intel () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_intel_atom () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_intel_core2 () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_intel_corei7 () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_intel_corei7_nehalem () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_intel_corei7_westmere () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_intel_corei7_sandybridge () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_amdfam10 () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_amdfam10_barcelona () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_amdfam10_shanghai () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_amdfam10_istanbul () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_amdfam15_bdver1 () < 0)
>> +    return -1;
>> +  if (__builtin_cpu_is_amdfam15_bdver2 () < 0)
>> +    return -1;
>> +
>> +  return 0;
>> +}
>> +
>> +int main ()
>> +{
>> +  return fn1 ();
>> +}
>>
>> --
>> This patch is available for review at http://codereview.appspot.com/5754058

On Thu, Mar 8, 2012 at 9:35 PM, Xinliang David Li <davidxl@google.com> wrote:
> On Wed, Mar 7, 2012 at 5:51 AM, Richard Guenther
> <richard.guenther@gmail.com> wrote:
>> On Wed, Mar 7, 2012 at 1:49 AM, Sriraman Tallam <tmsriram@google.com> wrote:
>>> Patch for CPU detection at run-time.
>>> ===================================
>>>
>>> Patch for CPU detection at run-time, to be used in dispatching of
>>> multi-versioned functions.   Please see this discussion:
>>> http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01355.html
>>> when this patch for reviewed the last time.
>>>
>>> For more detailed description:
>>> http://gcc.gnu.org/ml/gcc/2012-03/msg00074.html
>>>
>>> One of the main concerns was about making CPU detection initialization a
>>> constructor. The main point raised was about constructor ordering. I have
>>> added a priority value to the CPU detection constructor to make it very high
>>> priority so that it is guaranteed to fire before every constructor without
>>> an explicitly marked priority value of 101.  However, IFUNC initializers
>>> will still fire before this constructor, so the cpu initialization routine
>>> has to be explicitly called in such initializers for which I have added a
>>> builtin: __builtin_cpu_init ().
>>>
>>> This patch adds the following new builtins:
>>>
>>> * __builtin_cpu_init
>>> * __builtin_cpu_supports_cmov
>>> * __builtin_cpu_supports_mmx
>>> * __builtin_cpu_supports_popcount
>>> * __builtin_cpu_supports_sse
>>> * __builtin_cpu_supports_sse2
>>> * __builtin_cpu_supports_sse3
>>> * __builtin_cpu_supports_ssse3
>>> * __builtin_cpu_supports_sse4_1
>>> * __builtin_cpu_supports_sse4_2
>>> * __builtin_cpu_is_amd
>>> * __builtin_cpu_is_intel_atom
>>> * __builtin_cpu_is_intel_core2
>>> * __builtin_cpu_is_intel
>>> * __builtin_cpu_is_intel_corei7
>>> * __builtin_cpu_is_intel_corei7_nehalem
>>> * __builtin_cpu_is_intel_corei7_westmere
>>> * __builtin_cpu_is_intel_corei7_sandybridge
>>> * __builtin_cpu_is_amdfam10
>>> * __builtin_cpu_is_amdfam10_barcelona
>>> * __builtin_cpu_is_amdfam10_shanghai
>>> * __builtin_cpu_is_amdfam10_istanbul
>>> * __builtin_cpu_is_amdfam15_bdver1
>>> * __builtin_cpu_is_amdfam15_bdver2
>>
>> I think the non-feature detection functions are not necessary at all.
>
> They are useful if compiler needs to do auto versioning based on cpu model.
>
>> Builtin functions are not exactly cheap, nor is the scheme you invent
>> backward/forward compatible.  Instead, why not add a single builtin
>> function, __builtin_cpu_supports(const char *), and decode from
>> a comma-separated list of features?  Unknown features are simply
>> "not present".  So I can write code with only a single configure check,
>
> This is a good idea.
>
> __builtin_is_cpu (const char* );
> __builtin_cpu_supports (char char*);

That looks good to me.

Richard.

> thanks,
>
> David
>
>
>> for __builtin_cpu_supports, and cater for future features or older compilers.
>>
>> And of course that builtin would be even cross-platform.
>>
>> Implementation-wise I'll leave this to x86 maintainers to comment on.
>>
>> Richard.
>>
>>>
>>>        * config/i386/i386.c (build_struct_with_one_bit_fields): New function.
>>>        (make_var_decl): New function.
>>>        (get_field_from_struct): New function.
>>>        (fold_builtin_target): New function.
>>>        (ix86_fold_builtin): New function.
>>>        (ix86_expand_builtin): Expand new builtins by folding them.
>>>        (make_platform_builtin): New functions.
>>>        (ix86_init_platform_type_builtins): Make the new builtins.
>>>        (ix86_init_builtins): Make new builtins to detect CPU type.
>>>        (TARGET_FOLD_BUILTIN): New macro.
>>>        (IX86_BUILTIN_CPU_SUPPORTS_CMOV): New enum value.
>>>        (IX86_BUILTIN_CPU_SUPPORTS_MMX): New enum value.
>>>        (IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT): New enum value.
>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE): New enum value.
>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE2): New enum value.
>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE3): New enum value.
>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSSE3): New enum value.
>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_1): New enum value.
>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_2): New enum value.
>>>        (IX86_BUILTIN_CPU_INIT): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_AMD): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_INTEL): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_INTEL_ATOM): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_INTEL_CORE2): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_AMDFAM10_BARCELONA): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_AMDFAM10_SHANGHAI): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_AMDFAM10_ISTANBUL): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1): New enum value.
>>>        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2): New enum value.
>>>        * config/i386/i386-builtin-types.def: New function type.
>>>        * testsuite/gcc.target/builtin_target.c: New testcase.
>>>
>>>        * libgcc/config/i386/i386-cpuinfo.c: New file.
>>>        * libgcc/config/i386/t-cpuinfo: New file.
>>>        * libgcc/config.host: Include t-cpuinfo.
>>>        * libgcc/config/i386/libgcc-glibc.ver: Version symbols __cpu_model
>>>        and __cpu_features.
>>>
>>> Index: libgcc/config.host
>>> ===================================================================
>>> --- libgcc/config.host  (revision 184971)
>>> +++ libgcc/config.host  (working copy)
>>> @@ -1142,7 +1142,7 @@ i[34567]86-*-linux* | x86_64-*-linux* | \
>>>   i[34567]86-*-kfreebsd*-gnu | x86_64-*-kfreebsd*-gnu | \
>>>   i[34567]86-*-knetbsd*-gnu | \
>>>   i[34567]86-*-gnu*)
>>> -       tmake_file="${tmake_file} t-tls i386/t-linux"
>>> +       tmake_file="${tmake_file} t-tls i386/t-linux i386/t-cpuinfo"
>>>        if test "$libgcc_cv_cfi" = "yes"; then
>>>                tmake_file="${tmake_file} t-stack i386/t-stack-i386"
>>>        fi
>>> Index: libgcc/config/i386/t-cpuinfo
>>> ===================================================================
>>> --- libgcc/config/i386/t-cpuinfo        (revision 0)
>>> +++ libgcc/config/i386/t-cpuinfo        (revision 0)
>>> @@ -0,0 +1 @@
>>> +LIB2ADD += $(srcdir)/config/i386/i386-cpuinfo.c
>>> Index: libgcc/config/i386/i386-cpuinfo.c
>>> ===================================================================
>>> --- libgcc/config/i386/i386-cpuinfo.c   (revision 0)
>>> +++ libgcc/config/i386/i386-cpuinfo.c   (revision 0)
>>> @@ -0,0 +1,306 @@
>>> +/* Get CPU type and Features for x86 processors.
>>> +   Copyright (C) 2011 Free Software Foundation, Inc.
>>> +   Contributed by Sriraman Tallam (tmsriram@google.com)
>>> +
>>> +This file is part of GCC.
>>> +
>>> +GCC is free software; you can redistribute it and/or modify it under
>>> +the terms of the GNU General Public License as published by the Free
>>> +Software Foundation; either version 3, or (at your option) any later
>>> +version.
>>> +
>>> +GCC is distributed in the hope that it will be useful, but WITHOUT ANY
>>> +WARRANTY; without even the implied warranty of MERCHANTABILITY or
>>> +FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
>>> +for more details.
>>> +
>>> +You should have received a copy of the GNU General Public License
>>> +along with GCC; see the file COPYING3.  If not see
>>> +<http://www.gnu.org/licenses/>. */
>>> +
>>> +#include "cpuid.h"
>>> +#include "tsystem.h"
>>> +
>>> +int __cpu_indicator_init (void) __attribute__ ((constructor (101)));
>>> +
>>> +enum vendor_signatures
>>> +{
>>> +  SIG_INTEL =  0x756e6547 /* Genu */,
>>> +  SIG_AMD =    0x68747541 /* Auth */
>>> +};
>>> +
>>> +/* ISA Features supported. */
>>> +
>>> +struct __processor_features
>>> +{
>>> +  unsigned int __cpu_cmov : 1;
>>> +  unsigned int __cpu_mmx : 1;
>>> +  unsigned int __cpu_popcnt : 1;
>>> +  unsigned int __cpu_sse : 1;
>>> +  unsigned int __cpu_sse2 : 1;
>>> +  unsigned int __cpu_sse3 : 1;
>>> +  unsigned int __cpu_ssse3 : 1;
>>> +  unsigned int __cpu_sse4_1 : 1;
>>> +  unsigned int __cpu_sse4_2 : 1;
>>> +} __cpu_features;
>>> +
>>> +/* Processor Model. */
>>> +
>>> +struct __processor_model
>>> +{
>>> +  /* Vendor. */
>>> +  unsigned int __cpu_is_amd : 1;
>>> +  unsigned int __cpu_is_intel : 1;
>>> +  /* CPU type. */
>>> +  unsigned int __cpu_is_intel_atom : 1;
>>> +  unsigned int __cpu_is_intel_core2 : 1;
>>> +  unsigned int __cpu_is_intel_corei7 : 1;
>>> +  unsigned int __cpu_is_intel_corei7_nehalem : 1;
>>> +  unsigned int __cpu_is_intel_corei7_westmere : 1;
>>> +  unsigned int __cpu_is_intel_corei7_sandybridge : 1;
>>> +  unsigned int __cpu_is_amdfam10h : 1;
>>> +  unsigned int __cpu_is_amdfam10h_barcelona : 1;
>>> +  unsigned int __cpu_is_amdfam10h_shanghai : 1;
>>> +  unsigned int __cpu_is_amdfam10h_istanbul : 1;
>>> +  unsigned int __cpu_is_amdfam15h_bdver1 : 1;
>>> +  unsigned int __cpu_is_amdfam15h_bdver2 : 1;
>>> +} __cpu_model;
>>> +
>>> +/* Get the specific type of AMD CPU.  */
>>> +
>>> +static void
>>> +get_amd_cpu (unsigned int family, unsigned int model)
>>> +{
>>> +  switch (family)
>>> +    {
>>> +    /* AMD Family 10h.  */
>>> +    case 0x10:
>>> +      switch (model)
>>> +       {
>>> +       case 0x2:
>>> +         /* Barcelona.  */
>>> +         __cpu_model.__cpu_is_amdfam10h = 1;
>>> +         __cpu_model.__cpu_is_amdfam10h_barcelona = 1;
>>> +         break;
>>> +       case 0x4:
>>> +         /* Shanghai.  */
>>> +         __cpu_model.__cpu_is_amdfam10h = 1;
>>> +         __cpu_model.__cpu_is_amdfam10h_shanghai = 1;
>>> +         break;
>>> +       case 0x8:
>>> +         /* Istanbul.  */
>>> +         __cpu_model.__cpu_is_amdfam10h = 1;
>>> +         __cpu_model.__cpu_is_amdfam10h_istanbul = 1;
>>> +         break;
>>> +       default:
>>> +         break;
>>> +       }
>>> +      break;
>>> +    /* AMD Family 15h.  */
>>> +    case 0x15:
>>> +      /* Bulldozer version 1.  */
>>> +      if (model >= 0 && model <= 0xf)
>>> +        __cpu_model.__cpu_is_amdfam15h_bdver1 = 1;
>>> +      /* Bulldozer version 2.  */
>>> +      if (model >= 0x10 && model <= 0x1f)
>>> +        __cpu_model.__cpu_is_amdfam15h_bdver2 = 1;
>>> +      break;
>>> +    default:
>>> +      break;
>>> +    }
>>> +}
>>> +
>>> +/* Get the specific type of Intel CPU.  */
>>> +
>>> +static void
>>> +get_intel_cpu (unsigned int family, unsigned int model, unsigned int brand_id)
>>> +{
>>> +  /* Parse family and model only if brand ID is 0. */
>>> +  if (brand_id == 0)
>>> +    {
>>> +      switch (family)
>>> +       {
>>> +       case 0x5:
>>> +         /* Pentium.  */
>>> +         break;
>>> +       case 0x6:
>>> +         switch (model)
>>> +           {
>>> +           case 0x1c:
>>> +           case 0x26:
>>> +             /* Atom.  */
>>> +             __cpu_model.__cpu_is_intel_atom = 1;
>>> +             break;
>>> +           case 0x1a:
>>> +           case 0x1e:
>>> +           case 0x1f:
>>> +           case 0x2e:
>>> +             /* Nehalem.  */
>>> +             __cpu_model.__cpu_is_intel_corei7 = 1;
>>> +             __cpu_model.__cpu_is_intel_corei7_nehalem = 1;
>>> +             break;
>>> +           case 0x25:
>>> +           case 0x2c:
>>> +           case 0x2f:
>>> +             /* Westmere.  */
>>> +             __cpu_model.__cpu_is_intel_corei7 = 1;
>>> +             __cpu_model.__cpu_is_intel_corei7_westmere = 1;
>>> +             break;
>>> +           case 0x2a:
>>> +             /* Sandy Bridge.  */
>>> +             __cpu_model.__cpu_is_intel_corei7 = 1;
>>> +             __cpu_model.__cpu_is_intel_corei7_sandybridge = 1;
>>> +             break;
>>> +           case 0x17:
>>> +           case 0x1d:
>>> +             /* Penryn.  */
>>> +           case 0x0f:
>>> +             /* Merom.  */
>>> +             __cpu_model.__cpu_is_intel_core2 = 1;
>>> +             break;
>>> +           default:
>>> +             break;
>>> +           }
>>> +         break;
>>> +       default:
>>> +         /* We have no idea.  */
>>> +         break;
>>> +       }
>>> +    }
>>> +}
>>> +
>>> +static void
>>> +get_available_features (unsigned int ecx, unsigned int edx)
>>> +{
>>> +  __cpu_features.__cpu_cmov = (edx & bit_CMOV) ? 1 : 0;
>>> +  __cpu_features.__cpu_mmx = (edx & bit_MMX) ? 1 : 0;
>>> +  __cpu_features.__cpu_sse = (edx & bit_SSE) ? 1 : 0;
>>> +  __cpu_features.__cpu_sse2 = (edx & bit_SSE2) ? 1 : 0;
>>> +  __cpu_features.__cpu_popcnt = (ecx & bit_POPCNT) ? 1 : 0;
>>> +  __cpu_features.__cpu_sse3 = (ecx & bit_SSE3) ? 1 : 0;
>>> +  __cpu_features.__cpu_ssse3 = (ecx & bit_SSSE3) ? 1 : 0;
>>> +  __cpu_features.__cpu_sse4_1 = (ecx & bit_SSE4_1) ? 1 : 0;
>>> +  __cpu_features.__cpu_sse4_2 = (ecx & bit_SSE4_2) ? 1 : 0;
>>> +}
>>> +
>>> +
>>> +/* Sanity check for the vendor and cpu type flags.  */
>>> +
>>> +static int
>>> +sanity_check (void)
>>> +{
>>> +  unsigned int one_type = 0;
>>> +
>>> +  /* Vendor cannot be Intel and AMD. */
>>> +  gcc_assert((__cpu_model.__cpu_is_intel == 0)
>>> +             || (__cpu_model.__cpu_is_amd == 0));
>>> +
>>> +  /* Only one CPU type can be set. */
>>> +  one_type = (__cpu_model.__cpu_is_intel_atom
>>> +             + __cpu_model.__cpu_is_intel_core2
>>> +             + __cpu_model.__cpu_is_intel_corei7_nehalem
>>> +             + __cpu_model.__cpu_is_intel_corei7_westmere
>>> +             + __cpu_model.__cpu_is_intel_corei7_sandybridge
>>> +             + __cpu_model.__cpu_is_amdfam10h_barcelona
>>> +             + __cpu_model.__cpu_is_amdfam10h_shanghai
>>> +             + __cpu_model.__cpu_is_amdfam10h_istanbul
>>> +             + __cpu_model.__cpu_is_amdfam15h_bdver1
>>> +             + __cpu_model.__cpu_is_amdfam15h_bdver2);
>>> +
>>> +  gcc_assert (one_type <= 1);
>>> +  return 0;
>>> +}
>>> +
>>> +/* A noinline function calling __get_cpuid. Having many calls to
>>> +   cpuid in one function in 32-bit mode causes GCC to complain:
>>> +   "can’t find a register in class ‘CLOBBERED_REGS’".  This is
>>> +   related to PR rtl-optimization 44174. */
>>> +
>>> +static int __attribute__ ((noinline))
>>> +__get_cpuid_output (unsigned int __level,
>>> +                   unsigned int *__eax, unsigned int *__ebx,
>>> +                   unsigned int *__ecx, unsigned int *__edx)
>>> +{
>>> +  return __get_cpuid (__level, __eax, __ebx, __ecx, __edx);
>>> +}
>>> +
>>> +
>>> +/* A constructor function that is sets __cpu_model and __cpu_features with
>>> +   the right values.  This needs to run only once.  This constructor is
>>> +   given the highest priority and it should run before constructors without
>>> +   the priority set.  However, it still runs after ifunc initializers and
>>> +   needs to be called explicitly there.  */
>>> +
>>> +int __attribute__ ((constructor (101)))
>>> +__cpu_indicator_init (void)
>>> +{
>>> +  unsigned int eax, ebx, ecx, edx;
>>> +
>>> +  int max_level = 5;
>>> +  unsigned int vendor;
>>> +  unsigned int model, family, brand_id;
>>> +  unsigned int extended_model, extended_family;
>>> +  static int called = 0;
>>> +
>>> +  /* This function needs to run just once.  */
>>> +  if (called)
>>> +    return 0;
>>> +  else
>>> +    called = 1;
>>> +
>>> +  /* Assume cpuid insn present. Run in level 0 to get vendor id. */
>>> +  if (!__get_cpuid_output (0, &eax, &ebx, &ecx, &edx))
>>> +    return -1;
>>> +
>>> +  vendor = ebx;
>>> +  max_level = eax;
>>> +
>>> +  if (max_level < 1)
>>> +    return -1;
>>> +
>>> +  if (!__get_cpuid_output (1, &eax, &ebx, &ecx, &edx))
>>> +    return -1;
>>> +
>>> +  model = (eax >> 4) & 0x0f;
>>> +  family = (eax >> 8) & 0x0f;
>>> +  brand_id = ebx & 0xff;
>>> +  extended_model = (eax >> 12) & 0xf0;
>>> +  extended_family = (eax >> 20) & 0xff;
>>> +
>>> +  if (vendor == SIG_INTEL)
>>> +    {
>>> +      /* Adjust model and family for Intel CPUS. */
>>> +      if (family == 0x0f)
>>> +       {
>>> +         family += extended_family;
>>> +         model += extended_model;
>>> +       }
>>> +      else if (family == 0x06)
>>> +       model += extended_model;
>>> +
>>> +      /* Get CPU type.  */
>>> +      __cpu_model.__cpu_is_intel = 1;
>>> +      get_intel_cpu (family, model, brand_id);
>>> +    }
>>> +
>>> +  if (vendor == SIG_AMD)
>>> +    {
>>> +      /* Adjust model and family for AMD CPUS. */
>>> +      if (family == 0x0f)
>>> +       {
>>> +         family += extended_family;
>>> +         model += (extended_model << 4);
>>> +       }
>>> +
>>> +      /* Get CPU type.  */
>>> +      __cpu_model.__cpu_is_amd = 1;
>>> +      get_amd_cpu (family, model);
>>> +    }
>>> +
>>> +  /* Find available features. */
>>> +  get_available_features (ecx, edx);
>>> +
>>> +  sanity_check ();
>>> +
>>> +  return 0;
>>> +}
>>> Index: libgcc/config/i386/libgcc-glibc.ver
>>> ===================================================================
>>> --- libgcc/config/i386/libgcc-glibc.ver (revision 184971)
>>> +++ libgcc/config/i386/libgcc-glibc.ver (working copy)
>>> @@ -147,6 +147,11 @@ GCC_4.3.0 {
>>>   __trunctfxf2
>>>   __unordtf2
>>>  }
>>> +
>>> +GCC_4.8.0 {
>>> +  __cpu_model
>>> +  __cpu_features
>>> +}
>>>  %else
>>>  GCC_4.4.0 {
>>>   __addtf3
>>> @@ -183,4 +188,9 @@ GCC_4.4.0 {
>>>  GCC_4.5.0 {
>>>   __extendxftf2
>>>  }
>>> +
>>> +GCC_4.8.0 {
>>> +  __cpu_model
>>> +  __cpu_features
>>> +}
>>>  %endif
>>> Index: gcc/config/i386/i386-builtin-types.def
>>> ===================================================================
>>> --- gcc/config/i386/i386-builtin-types.def      (revision 184971)
>>> +++ gcc/config/i386/i386-builtin-types.def      (working copy)
>>> @@ -143,6 +143,7 @@ DEF_FUNCTION_TYPE (UINT64)
>>>  DEF_FUNCTION_TYPE (UNSIGNED)
>>>  DEF_FUNCTION_TYPE (VOID)
>>>  DEF_FUNCTION_TYPE (PVOID)
>>> +DEF_FUNCTION_TYPE (INT)
>>>
>>>  DEF_FUNCTION_TYPE (FLOAT, FLOAT)
>>>  DEF_FUNCTION_TYPE (FLOAT128, FLOAT128)
>>> Index: gcc/config/i386/i386.c
>>> ===================================================================
>>> --- gcc/config/i386/i386.c      (revision 184971)
>>> +++ gcc/config/i386/i386.c      (working copy)
>>> @@ -25637,6 +25637,33 @@ enum ix86_builtins
>>>   /* CFString built-in for darwin */
>>>   IX86_BUILTIN_CFSTRING,
>>>
>>> +  /* Builtins to get CPU features. */
>>> +  IX86_BUILTIN_CPU_SUPPORTS_CMOV,
>>> +  IX86_BUILTIN_CPU_SUPPORTS_MMX,
>>> +  IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT,
>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE,
>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE2,
>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE3,
>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSSE3,
>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE4_1,
>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE4_2,
>>> +  /* Builtins to get CPU type. */
>>> +  IX86_BUILTIN_CPU_INIT,
>>> +  IX86_BUILTIN_CPU_IS_AMD,
>>> +  IX86_BUILTIN_CPU_IS_INTEL,
>>> +  IX86_BUILTIN_CPU_IS_INTEL_ATOM,
>>> +  IX86_BUILTIN_CPU_IS_INTEL_CORE2,
>>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7,
>>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM,
>>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE,
>>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE,
>>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H,
>>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA,
>>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI,
>>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL,
>>> +  IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1,
>>> +  IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2,
>>> +
>>>   IX86_BUILTIN_MAX
>>>  };
>>>
>>> @@ -27446,6 +27473,593 @@ ix86_init_mmx_sse_builtins (void)
>>>     }
>>>  }
>>>
>>> +/* Returns a struct type with name NAME and number of fields equal to
>>> +   NUM_FIELDS.  Each field is a unsigned int bit field of length 1 bit. */
>>> +
>>> +static tree
>>> +build_struct_with_one_bit_fields (int num_fields, const char *name)
>>> +{
>>> +  int i;
>>> +  char field_name [10];
>>> +  tree field = NULL_TREE, field_chain = NULL_TREE;
>>> +  tree type = make_node (RECORD_TYPE);
>>> +
>>> +  strcpy (field_name, "k_field");
>>> +
>>> +  for (i = 0; i < num_fields; i++)
>>> +    {
>>> +      /* Name the fields, 0_field, 1_field, ... */
>>> +      field_name [0] = '0' + i;
>>> +      field = build_decl (UNKNOWN_LOCATION, FIELD_DECL,
>>> +                         get_identifier (field_name), unsigned_type_node);
>>> +      DECL_BIT_FIELD (field) = 1;
>>> +      DECL_SIZE (field) = bitsize_one_node;
>>> +      if (field_chain != NULL_TREE)
>>> +       DECL_CHAIN (field) = field_chain;
>>> +      field_chain = field;
>>> +    }
>>> +  finish_builtin_struct (type, name, field_chain, NULL_TREE);
>>> +  return type;
>>> +}
>>> +
>>> +/* Returns a extern, comdat VAR_DECL of type TYPE and name NAME. */
>>> +
>>> +static tree
>>> +make_var_decl (tree type, const char *name)
>>> +{
>>> +  tree new_decl;
>>> +  struct varpool_node *vnode;
>>> +
>>> +  new_decl = build_decl (UNKNOWN_LOCATION,
>>> +                        VAR_DECL,
>>> +                        get_identifier(name),
>>> +                        type);
>>> +
>>> +  DECL_EXTERNAL (new_decl) = 1;
>>> +  TREE_STATIC (new_decl) = 1;
>>> +  TREE_PUBLIC (new_decl) = 1;
>>> +  DECL_INITIAL (new_decl) = 0;
>>> +  DECL_ARTIFICIAL (new_decl) = 0;
>>> +  DECL_PRESERVE_P (new_decl) = 1;
>>> +
>>> +  make_decl_one_only (new_decl, DECL_ASSEMBLER_NAME (new_decl));
>>> +  assemble_variable (new_decl, 0, 0, 0);
>>> +
>>> +  vnode = varpool_node (new_decl);
>>> +  gcc_assert (vnode != NULL);
>>> +  /* Set finalized to 1, otherwise it asserts in function "write_symbol" in
>>> +     lto-streamer-out.c. */
>>> +  vnode->finalized = 1;
>>> +
>>> +  return new_decl;
>>> +}
>>> +
>>> +/* Traverses the chain of fields in STRUCT_TYPE and returns the FIELD_NUM
>>> +   numbered field. */
>>> +
>>> +static tree
>>> +get_field_from_struct (tree struct_type, int field_num)
>>> +{
>>> +  int i;
>>> +  tree field = TYPE_FIELDS (struct_type);
>>> +
>>> +  for (i = 0; i < field_num; i++, field = DECL_CHAIN(field))
>>> +    {
>>> +      gcc_assert (field != NULL_TREE);
>>> +    }
>>> +
>>> +  return field;
>>> +}
>>> +
>>> +/* FNDECL is a __builtin_cpu_* call that is folded into an integer defined
>>> +   in libgcc/config/i386/i386-cpuinfo.c */
>>> +
>>> +static tree
>>> +fold_builtin_cpu (enum ix86_builtins fn_code)
>>> +{
>>> +  /* This is the order of bit-fields in __processor_features in
>>> +     i386-cpuinfo.c */
>>> +  enum processor_features
>>> +  {
>>> +    F_CMOV = 0,
>>> +    F_MMX,
>>> +    F_POPCNT,
>>> +    F_SSE,
>>> +    F_SSE2,
>>> +    F_SSE3,
>>> +    F_SSSE3,
>>> +    F_SSE4_1,
>>> +    F_SSE4_2,
>>> +    F_MAX
>>> +  };
>>> +
>>> +  /* This is the order of bit-fields in __processor_model in
>>> +     i386-cpuinfo.c */
>>> +  enum processor_model
>>> +  {
>>> +    M_AMD = 0,
>>> +    M_INTEL,
>>> +    M_INTEL_ATOM,
>>> +    M_INTEL_CORE2,
>>> +    M_INTEL_COREI7,
>>> +    M_INTEL_COREI7_NEHALEM,
>>> +    M_INTEL_COREI7_WESTMERE,
>>> +    M_INTEL_COREI7_SANDYBRIDGE,
>>> +    M_AMDFAM10H,
>>> +    M_AMDFAM10H_BARCELONA,
>>> +    M_AMDFAM10H_SHANGHAI,
>>> +    M_AMDFAM10H_ISTANBUL,
>>> +    M_AMDFAM15H_BDVER1,
>>> +    M_AMDFAM15H_BDVER2,
>>> +    M_MAX
>>> +  };
>>> +
>>> +  static tree __processor_features_type = NULL_TREE;
>>> +  static tree __cpu_features_var = NULL_TREE;
>>> +  static tree __processor_model_type = NULL_TREE;
>>> +  static tree __cpu_model_var = NULL_TREE;
>>> +  static tree field;
>>> +  static tree which_struct;
>>> +
>>> +  if (__processor_features_type == NULL_TREE)
>>> +    __processor_features_type = build_struct_with_one_bit_fields (F_MAX,
>>> +                                 "__processor_features");
>>> +
>>> +  if (__processor_model_type == NULL_TREE)
>>> +    __processor_model_type = build_struct_with_one_bit_fields (M_MAX,
>>> +                                 "__processor_model");
>>> +
>>> +  if (__cpu_features_var == NULL_TREE)
>>> +    __cpu_features_var = make_var_decl (__processor_features_type,
>>> +                                       "__cpu_features");
>>> +
>>> +  if (__cpu_model_var == NULL_TREE)
>>> +    __cpu_model_var = make_var_decl (__processor_model_type,
>>> +                                    "__cpu_model");
>>> +
>>> +  /* Look at the code to identify the field requested. */
>>> +  switch (fn_code)
>>> +    {
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_CMOV:
>>> +      field = get_field_from_struct (__processor_features_type, F_CMOV);
>>> +      which_struct = __cpu_features_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_MMX:
>>> +      field = get_field_from_struct (__processor_features_type, F_MMX);
>>> +      which_struct = __cpu_features_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT:
>>> +      field = get_field_from_struct (__processor_features_type, F_POPCNT);
>>> +      which_struct = __cpu_features_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE:
>>> +      field = get_field_from_struct (__processor_features_type, F_SSE);
>>> +      which_struct = __cpu_features_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE2:
>>> +      field = get_field_from_struct (__processor_features_type, F_SSE2);
>>> +      which_struct = __cpu_features_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE3:
>>> +      field = get_field_from_struct (__processor_features_type, F_SSE3);
>>> +      which_struct = __cpu_features_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSSE3:
>>> +      field = get_field_from_struct (__processor_features_type, F_SSSE3);
>>> +      which_struct = __cpu_features_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_1:
>>> +      field = get_field_from_struct (__processor_features_type, F_SSE4_1);
>>> +      which_struct = __cpu_features_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_2:
>>> +      field = get_field_from_struct (__processor_features_type, F_SSE4_2);
>>> +      which_struct = __cpu_features_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_AMD:
>>> +      field = get_field_from_struct (__processor_model_type, M_AMD);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_INTEL:
>>> +      field = get_field_from_struct (__processor_model_type, M_INTEL);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_ATOM:
>>> +      field = get_field_from_struct (__processor_model_type, M_INTEL_ATOM);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_CORE2:
>>> +      field = get_field_from_struct (__processor_model_type, M_INTEL_CORE2);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_INTEL_COREI7);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_INTEL_COREI7_NEHALEM);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_INTEL_COREI7_WESTMERE);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_INTEL_COREI7_SANDYBRIDGE);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_AMDFAM10H);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_AMDFAM10H_BARCELONA);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_AMDFAM10H_SHANGHAI);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_AMDFAM10H_ISTANBUL);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_AMDFAM15H_BDVER1);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2:
>>> +      field = get_field_from_struct (__processor_model_type,
>>> +                                    M_AMDFAM15H_BDVER2);
>>> +      which_struct = __cpu_model_var;
>>> +      break;
>>> +    default:
>>> +      return NULL_TREE;
>>> +    }
>>> +
>>> +  return build3 (COMPONENT_REF, TREE_TYPE (field), which_struct, field, NULL_TREE);
>>> +}
>>> +
>>> +static tree
>>> +ix86_fold_builtin (tree fndecl, int n_args ATTRIBUTE_UNUSED,
>>> +                  tree *args ATTRIBUTE_UNUSED, bool ignore ATTRIBUTE_UNUSED)
>>> +{
>>> +  const char* decl_name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
>>> +  if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD
>>> +      && strstr(decl_name, "__builtin_cpu") != NULL)
>>> +    {
>>> +      enum ix86_builtins code = (enum ix86_builtins)
>>> +                               DECL_FUNCTION_CODE (fndecl);
>>> +      return fold_builtin_cpu (code);
>>> +    }
>>> +  return NULL_TREE;
>>> +}
>>> +
>>> +/* A builtin to init/return the cpu type or feature.  Returns an
>>> +   integer and the type is a const if IS_CONST is set. */
>>> +
>>> +static void
>>> +make_platform_builtin (const char* name, int code, int is_const)
>>> +{
>>> +  tree decl;
>>> +  tree type;
>>> +
>>> +  type = ix86_get_builtin_func_type (INT_FTYPE_VOID);
>>> +  decl = add_builtin_function (name, type, code, BUILT_IN_MD,
>>> +                              NULL, NULL_TREE);
>>> +  gcc_assert (decl != NULL_TREE);
>>> +  ix86_builtins[(int) code] = decl;
>>> +  if (is_const)
>>> +    TREE_READONLY (decl) = 1;
>>> +}
>>> +
>>> +/* Builtins to get CPU type and features supported. */
>>> +
>>> +static void
>>> +ix86_init_platform_type_builtins (void)
>>> +{
>>> +  make_platform_builtin ("__builtin_cpu_init",
>>> +                        IX86_BUILTIN_CPU_INIT, 0);
>>> +  make_platform_builtin ("__builtin_cpu_supports_cmov",
>>> +                        IX86_BUILTIN_CPU_SUPPORTS_CMOV, 1);
>>> +  make_platform_builtin ("__builtin_cpu_supports_mmx",
>>> +                        IX86_BUILTIN_CPU_SUPPORTS_MMX, 1);
>>> +  make_platform_builtin ("__builtin_cpu_supports_popcount",
>>> +                        IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT, 1);
>>> +  make_platform_builtin ("__builtin_cpu_supports_sse",
>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE, 1);
>>> +  make_platform_builtin ("__builtin_cpu_supports_sse2",
>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE2, 1);
>>> +  make_platform_builtin ("__builtin_cpu_supports_sse3",
>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE3, 1);
>>> +  make_platform_builtin ("__builtin_cpu_supports_ssse3",
>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSSE3, 1);
>>> +  make_platform_builtin ("__builtin_cpu_supports_sse4_1",
>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE4_1, 1);
>>> +  make_platform_builtin ("__builtin_cpu_supports_sse4_2",
>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE4_2, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_amd",
>>> +                        IX86_BUILTIN_CPU_IS_AMD, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_intel_atom",
>>> +                        IX86_BUILTIN_CPU_IS_INTEL_ATOM, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_intel_core2",
>>> +                        IX86_BUILTIN_CPU_IS_INTEL_CORE2, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_intel",
>>> +                        IX86_BUILTIN_CPU_IS_INTEL, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7",
>>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_nehalem",
>>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_westmere",
>>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_sandybridge",
>>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10",
>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_barcelona",
>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_shanghai",
>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_istanbul",
>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam15_bdver1",
>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1, 1);
>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam15_bdver2",
>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2, 1);
>>> +}
>>> +
>>>  /* Internal method for ix86_init_builtins.  */
>>>
>>>  static void
>>> @@ -27529,6 +28143,9 @@ ix86_init_builtins (void)
>>>
>>>   ix86_init_builtin_types ();
>>>
>>> +  /* Builtins to get CPU type and features. */
>>> +  ix86_init_platform_type_builtins ();
>>> +
>>>   /* TFmode support builtins.  */
>>>   def_builtin_const (0, "__builtin_infq",
>>>                     FLOAT128_FTYPE_VOID, IX86_BUILTIN_INFQ);
>>> @@ -29145,6 +29762,48 @@ ix86_expand_builtin (tree exp, rtx target, rtx sub
>>>   enum machine_mode mode0, mode1, mode2, mode3, mode4;
>>>   unsigned int fcode = DECL_FUNCTION_CODE (fndecl);
>>>
>>> +  /* For CPU builtins that can be folded, fold first and expand the fold.  */
>>> +  switch (fcode)
>>> +    {
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_CMOV:
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_MMX:
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT:
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE:
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE2:
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE3:
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSSE3:
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_1:
>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_2:
>>> +    case IX86_BUILTIN_CPU_IS_AMD:
>>> +    case IX86_BUILTIN_CPU_IS_INTEL:
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_ATOM:
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_CORE2:
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7:
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM:
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE:
>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE:
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H:
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA:
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI:
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL:
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1:
>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2:
>>> +      {
>>> +        tree fold_expr = fold_builtin_cpu ((enum ix86_builtins) fcode);
>>> +       gcc_assert (fold_expr != NULL_TREE);
>>> +        return expand_expr (fold_expr, target, mode, EXPAND_NORMAL);
>>> +      }
>>> +    case IX86_BUILTIN_CPU_INIT:
>>> +      {
>>> +       /* Make it call __cpu_indicator_init in libgcc. */
>>> +       tree call_expr, fndecl, type;
>>> +        type = build_function_type_list (integer_type_node, NULL_TREE);
>>> +       fndecl = build_fn_decl ("__cpu_indicator_init", type);
>>> +       call_expr = build_call_expr (fndecl, 0);
>>> +       return expand_expr (call_expr, target, mode, EXPAND_NORMAL);
>>> +      }
>>> +    }
>>> +
>>>   /* Determine whether the builtin function is available under the current ISA.
>>>      Originally the builtin was not created if it wasn't applicable to the
>>>      current ISA based on the command line switches.  With function specific
>>> @@ -38610,6 +39269,12 @@ ix86_autovectorize_vector_sizes (void)
>>>  #undef TARGET_BUILD_BUILTIN_VA_LIST
>>>  #define TARGET_BUILD_BUILTIN_VA_LIST ix86_build_builtin_va_list
>>>
>>> +#undef TARGET_FOLD_BUILTIN
>>> +#define TARGET_FOLD_BUILTIN ix86_fold_builtin
>>> +
>>>  #undef TARGET_ENUM_VA_LIST_P
>>>  #define TARGET_ENUM_VA_LIST_P ix86_enum_va_list
>>> Index: gcc/testsuite/gcc.target/i386/builtin_target.c
>>> ===================================================================
>>> --- gcc/testsuite/gcc.target/i386/builtin_target.c      (revision 0)
>>> +++ gcc/testsuite/gcc.target/i386/builtin_target.c      (revision 0)
>>> @@ -0,0 +1,61 @@
>>> +/* This test checks if the __builtin_cpu_* calls are recognized. */
>>> +
>>> +/* { dg-do run } */
>>> +
>>> +int
>>> +fn1 ()
>>> +{
>>> +  if (__builtin_cpu_supports_cmov () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_supports_mmx () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_supports_popcount () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_supports_sse () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_supports_sse2 () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_supports_sse3 () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_supports_ssse3 () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_supports_sse4_1 () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_supports_sse4_2 () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_amd () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_intel () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_intel_atom () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_intel_core2 () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_intel_corei7 () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_intel_corei7_nehalem () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_intel_corei7_westmere () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_intel_corei7_sandybridge () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_amdfam10 () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_amdfam10_barcelona () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_amdfam10_shanghai () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_amdfam10_istanbul () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_amdfam15_bdver1 () < 0)
>>> +    return -1;
>>> +  if (__builtin_cpu_is_amdfam15_bdver2 () < 0)
>>> +    return -1;
>>> +
>>> +  return 0;
>>> +}
>>> +
>>> +int main ()
>>> +{
>>> +  return fn1 ();
>>> +}
>>>
>>> --
>>> This patch is available for review at http://codereview.appspot.com/5754058

Subject:Support for Runtime CPU type detection via builtins

Hi,

   I have uploaded a new patch to only have two builtins :

* __builtin_cpu_is ("<CPUNAME>")
* __builtin_cpu_supports ("<FEATURE>")

apart from the cpu init builtin, __builtin_cpu_init.

List of CPU names :

* "amd"
* "intel"
* "atom"
* "core2"
* "corei7"
* "nehalem"
* "westmere"
* "sandybridge"
* "amdfam10h"
* "barcelona"
* "shanghai"
* "istanbul"
* "bdver1"
* "bdver2"

List of CPU features :

* "cmov"
* "mmx"
* "popcnt"
* "sse"
* "sse2"
* "sse3"
* "ssse3"
* "sse4.1"
* "sse4.2"

As an example, to check if CPU is corei7, call __builtin_cpu_is ("corei7")

Comments?
Thanks.

On Mon, Mar 12, 2012 at 4:16 AM, Richard Guenther
<richard.guenther@gmail.com> wrote:
> On Thu, Mar 8, 2012 at 9:35 PM, Xinliang David Li <davidxl@google.com> wrote:
>> On Wed, Mar 7, 2012 at 5:51 AM, Richard Guenther
>> <richard.guenther@gmail.com> wrote:
>>> On Wed, Mar 7, 2012 at 1:49 AM, Sriraman Tallam <tmsriram@google.com> wrote:
>>>> Patch for CPU detection at run-time.
>>>> ===================================
>>>>
>>>> Patch for CPU detection at run-time, to be used in dispatching of
>>>> multi-versioned functions.   Please see this discussion:
>>>> http://gcc.gnu.org/ml/gcc-patches/2011-08/msg01355.html
>>>> when this patch for reviewed the last time.
>>>>
>>>> For more detailed description:
>>>> http://gcc.gnu.org/ml/gcc/2012-03/msg00074.html
>>>>
>>>> One of the main concerns was about making CPU detection initialization a
>>>> constructor. The main point raised was about constructor ordering. I have
>>>> added a priority value to the CPU detection constructor to make it very high
>>>> priority so that it is guaranteed to fire before every constructor without
>>>> an explicitly marked priority value of 101.  However, IFUNC initializers
>>>> will still fire before this constructor, so the cpu initialization routine
>>>> has to be explicitly called in such initializers for which I have added a
>>>> builtin: __builtin_cpu_init ().
>>>>
>>>> This patch adds the following new builtins:
>>>>
>>>> * __builtin_cpu_init
>>>> * __builtin_cpu_supports_cmov
>>>> * __builtin_cpu_supports_mmx
>>>> * __builtin_cpu_supports_popcount
>>>> * __builtin_cpu_supports_sse
>>>> * __builtin_cpu_supports_sse2
>>>> * __builtin_cpu_supports_sse3
>>>> * __builtin_cpu_supports_ssse3
>>>> * __builtin_cpu_supports_sse4_1
>>>> * __builtin_cpu_supports_sse4_2
>>>> * __builtin_cpu_is_amd
>>>> * __builtin_cpu_is_intel_atom
>>>> * __builtin_cpu_is_intel_core2
>>>> * __builtin_cpu_is_intel
>>>> * __builtin_cpu_is_intel_corei7
>>>> * __builtin_cpu_is_intel_corei7_nehalem
>>>> * __builtin_cpu_is_intel_corei7_westmere
>>>> * __builtin_cpu_is_intel_corei7_sandybridge
>>>> * __builtin_cpu_is_amdfam10
>>>> * __builtin_cpu_is_amdfam10_barcelona
>>>> * __builtin_cpu_is_amdfam10_shanghai
>>>> * __builtin_cpu_is_amdfam10_istanbul
>>>> * __builtin_cpu_is_amdfam15_bdver1
>>>> * __builtin_cpu_is_amdfam15_bdver2
>>>
>>> I think the non-feature detection functions are not necessary at all.
>>
>> They are useful if compiler needs to do auto versioning based on cpu model.
>>
>>> Builtin functions are not exactly cheap, nor is the scheme you invent
>>> backward/forward compatible.  Instead, why not add a single builtin
>>> function, __builtin_cpu_supports(const char *), and decode from
>>> a comma-separated list of features?  Unknown features are simply
>>> "not present".  So I can write code with only a single configure check,
>>
>> This is a good idea.
>>
>> __builtin_is_cpu (const char* );
>> __builtin_cpu_supports (char char*);
>
> That looks good to me.
>
> Richard.
>
>> thanks,
>>
>> David
>>
>>
>>> for __builtin_cpu_supports, and cater for future features or older compilers.
>>>
>>> And of course that builtin would be even cross-platform.
>>>
>>> Implementation-wise I'll leave this to x86 maintainers to comment on.
>>>
>>> Richard.
>>>
>>>>
>>>>        * config/i386/i386.c (build_struct_with_one_bit_fields): New function.
>>>>        (make_var_decl): New function.
>>>>        (get_field_from_struct): New function.
>>>>        (fold_builtin_target): New function.
>>>>        (ix86_fold_builtin): New function.
>>>>        (ix86_expand_builtin): Expand new builtins by folding them.
>>>>        (make_platform_builtin): New functions.
>>>>        (ix86_init_platform_type_builtins): Make the new builtins.
>>>>        (ix86_init_builtins): Make new builtins to detect CPU type.
>>>>        (TARGET_FOLD_BUILTIN): New macro.
>>>>        (IX86_BUILTIN_CPU_SUPPORTS_CMOV): New enum value.
>>>>        (IX86_BUILTIN_CPU_SUPPORTS_MMX): New enum value.
>>>>        (IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT): New enum value.
>>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE): New enum value.
>>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE2): New enum value.
>>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE3): New enum value.
>>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSSE3): New enum value.
>>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_1): New enum value.
>>>>        (IX86_BUILTIN_CPU_SUPPORTS_SSE4_2): New enum value.
>>>>        (IX86_BUILTIN_CPU_INIT): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_AMD): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_INTEL): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_INTEL_ATOM): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_INTEL_CORE2): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_AMDFAM10_BARCELONA): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_AMDFAM10_SHANGHAI): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_AMDFAM10_ISTANBUL): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1): New enum value.
>>>>        (IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2): New enum value.
>>>>        * config/i386/i386-builtin-types.def: New function type.
>>>>        * testsuite/gcc.target/builtin_target.c: New testcase.
>>>>
>>>>        * libgcc/config/i386/i386-cpuinfo.c: New file.
>>>>        * libgcc/config/i386/t-cpuinfo: New file.
>>>>        * libgcc/config.host: Include t-cpuinfo.
>>>>        * libgcc/config/i386/libgcc-glibc.ver: Version symbols __cpu_model
>>>>        and __cpu_features.
>>>>
>>>> Index: libgcc/config.host
>>>> ===================================================================
>>>> --- libgcc/config.host  (revision 184971)
>>>> +++ libgcc/config.host  (working copy)
>>>> @@ -1142,7 +1142,7 @@ i[34567]86-*-linux* | x86_64-*-linux* | \
>>>>   i[34567]86-*-kfreebsd*-gnu | x86_64-*-kfreebsd*-gnu | \
>>>>   i[34567]86-*-knetbsd*-gnu | \
>>>>   i[34567]86-*-gnu*)
>>>> -       tmake_file="${tmake_file} t-tls i386/t-linux"
>>>> +       tmake_file="${tmake_file} t-tls i386/t-linux i386/t-cpuinfo"
>>>>        if test "$libgcc_cv_cfi" = "yes"; then
>>>>                tmake_file="${tmake_file} t-stack i386/t-stack-i386"
>>>>        fi
>>>> Index: libgcc/config/i386/t-cpuinfo
>>>> ===================================================================
>>>> --- libgcc/config/i386/t-cpuinfo        (revision 0)
>>>> +++ libgcc/config/i386/t-cpuinfo        (revision 0)
>>>> @@ -0,0 +1 @@
>>>> +LIB2ADD += $(srcdir)/config/i386/i386-cpuinfo.c
>>>> Index: libgcc/config/i386/i386-cpuinfo.c
>>>> ===================================================================
>>>> --- libgcc/config/i386/i386-cpuinfo.c   (revision 0)
>>>> +++ libgcc/config/i386/i386-cpuinfo.c   (revision 0)
>>>> @@ -0,0 +1,306 @@
>>>> +/* Get CPU type and Features for x86 processors.
>>>> +   Copyright (C) 2011 Free Software Foundation, Inc.
>>>> +   Contributed by Sriraman Tallam (tmsriram@google.com)
>>>> +
>>>> +This file is part of GCC.
>>>> +
>>>> +GCC is free software; you can redistribute it and/or modify it under
>>>> +the terms of the GNU General Public License as published by the Free
>>>> +Software Foundation; either version 3, or (at your option) any later
>>>> +version.
>>>> +
>>>> +GCC is distributed in the hope that it will be useful, but WITHOUT ANY
>>>> +WARRANTY; without even the implied warranty of MERCHANTABILITY or
>>>> +FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
>>>> +for more details.
>>>> +
>>>> +You should have received a copy of the GNU General Public License
>>>> +along with GCC; see the file COPYING3.  If not see
>>>> +<http://www.gnu.org/licenses/>. */
>>>> +
>>>> +#include "cpuid.h"
>>>> +#include "tsystem.h"
>>>> +
>>>> +int __cpu_indicator_init (void) __attribute__ ((constructor (101)));
>>>> +
>>>> +enum vendor_signatures
>>>> +{
>>>> +  SIG_INTEL =  0x756e6547 /* Genu */,
>>>> +  SIG_AMD =    0x68747541 /* Auth */
>>>> +};
>>>> +
>>>> +/* ISA Features supported. */
>>>> +
>>>> +struct __processor_features
>>>> +{
>>>> +  unsigned int __cpu_cmov : 1;
>>>> +  unsigned int __cpu_mmx : 1;
>>>> +  unsigned int __cpu_popcnt : 1;
>>>> +  unsigned int __cpu_sse : 1;
>>>> +  unsigned int __cpu_sse2 : 1;
>>>> +  unsigned int __cpu_sse3 : 1;
>>>> +  unsigned int __cpu_ssse3 : 1;
>>>> +  unsigned int __cpu_sse4_1 : 1;
>>>> +  unsigned int __cpu_sse4_2 : 1;
>>>> +} __cpu_features;
>>>> +
>>>> +/* Processor Model. */
>>>> +
>>>> +struct __processor_model
>>>> +{
>>>> +  /* Vendor. */
>>>> +  unsigned int __cpu_is_amd : 1;
>>>> +  unsigned int __cpu_is_intel : 1;
>>>> +  /* CPU type. */
>>>> +  unsigned int __cpu_is_intel_atom : 1;
>>>> +  unsigned int __cpu_is_intel_core2 : 1;
>>>> +  unsigned int __cpu_is_intel_corei7 : 1;
>>>> +  unsigned int __cpu_is_intel_corei7_nehalem : 1;
>>>> +  unsigned int __cpu_is_intel_corei7_westmere : 1;
>>>> +  unsigned int __cpu_is_intel_corei7_sandybridge : 1;
>>>> +  unsigned int __cpu_is_amdfam10h : 1;
>>>> +  unsigned int __cpu_is_amdfam10h_barcelona : 1;
>>>> +  unsigned int __cpu_is_amdfam10h_shanghai : 1;
>>>> +  unsigned int __cpu_is_amdfam10h_istanbul : 1;
>>>> +  unsigned int __cpu_is_amdfam15h_bdver1 : 1;
>>>> +  unsigned int __cpu_is_amdfam15h_bdver2 : 1;
>>>> +} __cpu_model;
>>>> +
>>>> +/* Get the specific type of AMD CPU.  */
>>>> +
>>>> +static void
>>>> +get_amd_cpu (unsigned int family, unsigned int model)
>>>> +{
>>>> +  switch (family)
>>>> +    {
>>>> +    /* AMD Family 10h.  */
>>>> +    case 0x10:
>>>> +      switch (model)
>>>> +       {
>>>> +       case 0x2:
>>>> +         /* Barcelona.  */
>>>> +         __cpu_model.__cpu_is_amdfam10h = 1;
>>>> +         __cpu_model.__cpu_is_amdfam10h_barcelona = 1;
>>>> +         break;
>>>> +       case 0x4:
>>>> +         /* Shanghai.  */
>>>> +         __cpu_model.__cpu_is_amdfam10h = 1;
>>>> +         __cpu_model.__cpu_is_amdfam10h_shanghai = 1;
>>>> +         break;
>>>> +       case 0x8:
>>>> +         /* Istanbul.  */
>>>> +         __cpu_model.__cpu_is_amdfam10h = 1;
>>>> +         __cpu_model.__cpu_is_amdfam10h_istanbul = 1;
>>>> +         break;
>>>> +       default:
>>>> +         break;
>>>> +       }
>>>> +      break;
>>>> +    /* AMD Family 15h.  */
>>>> +    case 0x15:
>>>> +      /* Bulldozer version 1.  */
>>>> +      if (model >= 0 && model <= 0xf)
>>>> +        __cpu_model.__cpu_is_amdfam15h_bdver1 = 1;
>>>> +      /* Bulldozer version 2.  */
>>>> +      if (model >= 0x10 && model <= 0x1f)
>>>> +        __cpu_model.__cpu_is_amdfam15h_bdver2 = 1;
>>>> +      break;
>>>> +    default:
>>>> +      break;
>>>> +    }
>>>> +}
>>>> +
>>>> +/* Get the specific type of Intel CPU.  */
>>>> +
>>>> +static void
>>>> +get_intel_cpu (unsigned int family, unsigned int model, unsigned int brand_id)
>>>> +{
>>>> +  /* Parse family and model only if brand ID is 0. */
>>>> +  if (brand_id == 0)
>>>> +    {
>>>> +      switch (family)
>>>> +       {
>>>> +       case 0x5:
>>>> +         /* Pentium.  */
>>>> +         break;
>>>> +       case 0x6:
>>>> +         switch (model)
>>>> +           {
>>>> +           case 0x1c:
>>>> +           case 0x26:
>>>> +             /* Atom.  */
>>>> +             __cpu_model.__cpu_is_intel_atom = 1;
>>>> +             break;
>>>> +           case 0x1a:
>>>> +           case 0x1e:
>>>> +           case 0x1f:
>>>> +           case 0x2e:
>>>> +             /* Nehalem.  */
>>>> +             __cpu_model.__cpu_is_intel_corei7 = 1;
>>>> +             __cpu_model.__cpu_is_intel_corei7_nehalem = 1;
>>>> +             break;
>>>> +           case 0x25:
>>>> +           case 0x2c:
>>>> +           case 0x2f:
>>>> +             /* Westmere.  */
>>>> +             __cpu_model.__cpu_is_intel_corei7 = 1;
>>>> +             __cpu_model.__cpu_is_intel_corei7_westmere = 1;
>>>> +             break;
>>>> +           case 0x2a:
>>>> +             /* Sandy Bridge.  */
>>>> +             __cpu_model.__cpu_is_intel_corei7 = 1;
>>>> +             __cpu_model.__cpu_is_intel_corei7_sandybridge = 1;
>>>> +             break;
>>>> +           case 0x17:
>>>> +           case 0x1d:
>>>> +             /* Penryn.  */
>>>> +           case 0x0f:
>>>> +             /* Merom.  */
>>>> +             __cpu_model.__cpu_is_intel_core2 = 1;
>>>> +             break;
>>>> +           default:
>>>> +             break;
>>>> +           }
>>>> +         break;
>>>> +       default:
>>>> +         /* We have no idea.  */
>>>> +         break;
>>>> +       }
>>>> +    }
>>>> +}
>>>> +
>>>> +static void
>>>> +get_available_features (unsigned int ecx, unsigned int edx)
>>>> +{
>>>> +  __cpu_features.__cpu_cmov = (edx & bit_CMOV) ? 1 : 0;
>>>> +  __cpu_features.__cpu_mmx = (edx & bit_MMX) ? 1 : 0;
>>>> +  __cpu_features.__cpu_sse = (edx & bit_SSE) ? 1 : 0;
>>>> +  __cpu_features.__cpu_sse2 = (edx & bit_SSE2) ? 1 : 0;
>>>> +  __cpu_features.__cpu_popcnt = (ecx & bit_POPCNT) ? 1 : 0;
>>>> +  __cpu_features.__cpu_sse3 = (ecx & bit_SSE3) ? 1 : 0;
>>>> +  __cpu_features.__cpu_ssse3 = (ecx & bit_SSSE3) ? 1 : 0;
>>>> +  __cpu_features.__cpu_sse4_1 = (ecx & bit_SSE4_1) ? 1 : 0;
>>>> +  __cpu_features.__cpu_sse4_2 = (ecx & bit_SSE4_2) ? 1 : 0;
>>>> +}
>>>> +
>>>> +
>>>> +/* Sanity check for the vendor and cpu type flags.  */
>>>> +
>>>> +static int
>>>> +sanity_check (void)
>>>> +{
>>>> +  unsigned int one_type = 0;
>>>> +
>>>> +  /* Vendor cannot be Intel and AMD. */
>>>> +  gcc_assert((__cpu_model.__cpu_is_intel == 0)
>>>> +             || (__cpu_model.__cpu_is_amd == 0));
>>>> +
>>>> +  /* Only one CPU type can be set. */
>>>> +  one_type = (__cpu_model.__cpu_is_intel_atom
>>>> +             + __cpu_model.__cpu_is_intel_core2
>>>> +             + __cpu_model.__cpu_is_intel_corei7_nehalem
>>>> +             + __cpu_model.__cpu_is_intel_corei7_westmere
>>>> +             + __cpu_model.__cpu_is_intel_corei7_sandybridge
>>>> +             + __cpu_model.__cpu_is_amdfam10h_barcelona
>>>> +             + __cpu_model.__cpu_is_amdfam10h_shanghai
>>>> +             + __cpu_model.__cpu_is_amdfam10h_istanbul
>>>> +             + __cpu_model.__cpu_is_amdfam15h_bdver1
>>>> +             + __cpu_model.__cpu_is_amdfam15h_bdver2);
>>>> +
>>>> +  gcc_assert (one_type <= 1);
>>>> +  return 0;
>>>> +}
>>>> +
>>>> +/* A noinline function calling __get_cpuid. Having many calls to
>>>> +   cpuid in one function in 32-bit mode causes GCC to complain:
>>>> +   "can’t find a register in class ‘CLOBBERED_REGS’".  This is
>>>> +   related to PR rtl-optimization 44174. */
>>>> +
>>>> +static int __attribute__ ((noinline))
>>>> +__get_cpuid_output (unsigned int __level,
>>>> +                   unsigned int *__eax, unsigned int *__ebx,
>>>> +                   unsigned int *__ecx, unsigned int *__edx)
>>>> +{
>>>> +  return __get_cpuid (__level, __eax, __ebx, __ecx, __edx);
>>>> +}
>>>> +
>>>> +
>>>> +/* A constructor function that is sets __cpu_model and __cpu_features with
>>>> +   the right values.  This needs to run only once.  This constructor is
>>>> +   given the highest priority and it should run before constructors without
>>>> +   the priority set.  However, it still runs after ifunc initializers and
>>>> +   needs to be called explicitly there.  */
>>>> +
>>>> +int __attribute__ ((constructor (101)))
>>>> +__cpu_indicator_init (void)
>>>> +{
>>>> +  unsigned int eax, ebx, ecx, edx;
>>>> +
>>>> +  int max_level = 5;
>>>> +  unsigned int vendor;
>>>> +  unsigned int model, family, brand_id;
>>>> +  unsigned int extended_model, extended_family;
>>>> +  static int called = 0;
>>>> +
>>>> +  /* This function needs to run just once.  */
>>>> +  if (called)
>>>> +    return 0;
>>>> +  else
>>>> +    called = 1;
>>>> +
>>>> +  /* Assume cpuid insn present. Run in level 0 to get vendor id. */
>>>> +  if (!__get_cpuid_output (0, &eax, &ebx, &ecx, &edx))
>>>> +    return -1;
>>>> +
>>>> +  vendor = ebx;
>>>> +  max_level = eax;
>>>> +
>>>> +  if (max_level < 1)
>>>> +    return -1;
>>>> +
>>>> +  if (!__get_cpuid_output (1, &eax, &ebx, &ecx, &edx))
>>>> +    return -1;
>>>> +
>>>> +  model = (eax >> 4) & 0x0f;
>>>> +  family = (eax >> 8) & 0x0f;
>>>> +  brand_id = ebx & 0xff;
>>>> +  extended_model = (eax >> 12) & 0xf0;
>>>> +  extended_family = (eax >> 20) & 0xff;
>>>> +
>>>> +  if (vendor == SIG_INTEL)
>>>> +    {
>>>> +      /* Adjust model and family for Intel CPUS. */
>>>> +      if (family == 0x0f)
>>>> +       {
>>>> +         family += extended_family;
>>>> +         model += extended_model;
>>>> +       }
>>>> +      else if (family == 0x06)
>>>> +       model += extended_model;
>>>> +
>>>> +      /* Get CPU type.  */
>>>> +      __cpu_model.__cpu_is_intel = 1;
>>>> +      get_intel_cpu (family, model, brand_id);
>>>> +    }
>>>> +
>>>> +  if (vendor == SIG_AMD)
>>>> +    {
>>>> +      /* Adjust model and family for AMD CPUS. */
>>>> +      if (family == 0x0f)
>>>> +       {
>>>> +         family += extended_family;
>>>> +         model += (extended_model << 4);
>>>> +       }
>>>> +
>>>> +      /* Get CPU type.  */
>>>> +      __cpu_model.__cpu_is_amd = 1;
>>>> +      get_amd_cpu (family, model);
>>>> +    }
>>>> +
>>>> +  /* Find available features. */
>>>> +  get_available_features (ecx, edx);
>>>> +
>>>> +  sanity_check ();
>>>> +
>>>> +  return 0;
>>>> +}
>>>> Index: libgcc/config/i386/libgcc-glibc.ver
>>>> ===================================================================
>>>> --- libgcc/config/i386/libgcc-glibc.ver (revision 184971)
>>>> +++ libgcc/config/i386/libgcc-glibc.ver (working copy)
>>>> @@ -147,6 +147,11 @@ GCC_4.3.0 {
>>>>   __trunctfxf2
>>>>   __unordtf2
>>>>  }
>>>> +
>>>> +GCC_4.8.0 {
>>>> +  __cpu_model
>>>> +  __cpu_features
>>>> +}
>>>>  %else
>>>>  GCC_4.4.0 {
>>>>   __addtf3
>>>> @@ -183,4 +188,9 @@ GCC_4.4.0 {
>>>>  GCC_4.5.0 {
>>>>   __extendxftf2
>>>>  }
>>>> +
>>>> +GCC_4.8.0 {
>>>> +  __cpu_model
>>>> +  __cpu_features
>>>> +}
>>>>  %endif
>>>> Index: gcc/config/i386/i386-builtin-types.def
>>>> ===================================================================
>>>> --- gcc/config/i386/i386-builtin-types.def      (revision 184971)
>>>> +++ gcc/config/i386/i386-builtin-types.def      (working copy)
>>>> @@ -143,6 +143,7 @@ DEF_FUNCTION_TYPE (UINT64)
>>>>  DEF_FUNCTION_TYPE (UNSIGNED)
>>>>  DEF_FUNCTION_TYPE (VOID)
>>>>  DEF_FUNCTION_TYPE (PVOID)
>>>> +DEF_FUNCTION_TYPE (INT)
>>>>
>>>>  DEF_FUNCTION_TYPE (FLOAT, FLOAT)
>>>>  DEF_FUNCTION_TYPE (FLOAT128, FLOAT128)
>>>> Index: gcc/config/i386/i386.c
>>>> ===================================================================
>>>> --- gcc/config/i386/i386.c      (revision 184971)
>>>> +++ gcc/config/i386/i386.c      (working copy)
>>>> @@ -25637,6 +25637,33 @@ enum ix86_builtins
>>>>   /* CFString built-in for darwin */
>>>>   IX86_BUILTIN_CFSTRING,
>>>>
>>>> +  /* Builtins to get CPU features. */
>>>> +  IX86_BUILTIN_CPU_SUPPORTS_CMOV,
>>>> +  IX86_BUILTIN_CPU_SUPPORTS_MMX,
>>>> +  IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT,
>>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE,
>>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE2,
>>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE3,
>>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSSE3,
>>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE4_1,
>>>> +  IX86_BUILTIN_CPU_SUPPORTS_SSE4_2,
>>>> +  /* Builtins to get CPU type. */
>>>> +  IX86_BUILTIN_CPU_INIT,
>>>> +  IX86_BUILTIN_CPU_IS_AMD,
>>>> +  IX86_BUILTIN_CPU_IS_INTEL,
>>>> +  IX86_BUILTIN_CPU_IS_INTEL_ATOM,
>>>> +  IX86_BUILTIN_CPU_IS_INTEL_CORE2,
>>>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7,
>>>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM,
>>>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE,
>>>> +  IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE,
>>>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H,
>>>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA,
>>>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI,
>>>> +  IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL,
>>>> +  IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1,
>>>> +  IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2,
>>>> +
>>>>   IX86_BUILTIN_MAX
>>>>  };
>>>>
>>>> @@ -27446,6 +27473,593 @@ ix86_init_mmx_sse_builtins (void)
>>>>     }
>>>>  }
>>>>
>>>> +/* Returns a struct type with name NAME and number of fields equal to
>>>> +   NUM_FIELDS.  Each field is a unsigned int bit field of length 1 bit. */
>>>> +
>>>> +static tree
>>>> +build_struct_with_one_bit_fields (int num_fields, const char *name)
>>>> +{
>>>> +  int i;
>>>> +  char field_name [10];
>>>> +  tree field = NULL_TREE, field_chain = NULL_TREE;
>>>> +  tree type = make_node (RECORD_TYPE);
>>>> +
>>>> +  strcpy (field_name, "k_field");
>>>> +
>>>> +  for (i = 0; i < num_fields; i++)
>>>> +    {
>>>> +      /* Name the fields, 0_field, 1_field, ... */
>>>> +      field_name [0] = '0' + i;
>>>> +      field = build_decl (UNKNOWN_LOCATION, FIELD_DECL,
>>>> +                         get_identifier (field_name), unsigned_type_node);
>>>> +      DECL_BIT_FIELD (field) = 1;
>>>> +      DECL_SIZE (field) = bitsize_one_node;
>>>> +      if (field_chain != NULL_TREE)
>>>> +       DECL_CHAIN (field) = field_chain;
>>>> +      field_chain = field;
>>>> +    }
>>>> +  finish_builtin_struct (type, name, field_chain, NULL_TREE);
>>>> +  return type;
>>>> +}
>>>> +
>>>> +/* Returns a extern, comdat VAR_DECL of type TYPE and name NAME. */
>>>> +
>>>> +static tree
>>>> +make_var_decl (tree type, const char *name)
>>>> +{
>>>> +  tree new_decl;
>>>> +  struct varpool_node *vnode;
>>>> +
>>>> +  new_decl = build_decl (UNKNOWN_LOCATION,
>>>> +                        VAR_DECL,
>>>> +                        get_identifier(name),
>>>> +                        type);
>>>> +
>>>> +  DECL_EXTERNAL (new_decl) = 1;
>>>> +  TREE_STATIC (new_decl) = 1;
>>>> +  TREE_PUBLIC (new_decl) = 1;
>>>> +  DECL_INITIAL (new_decl) = 0;
>>>> +  DECL_ARTIFICIAL (new_decl) = 0;
>>>> +  DECL_PRESERVE_P (new_decl) = 1;
>>>> +
>>>> +  make_decl_one_only (new_decl, DECL_ASSEMBLER_NAME (new_decl));
>>>> +  assemble_variable (new_decl, 0, 0, 0);
>>>> +
>>>> +  vnode = varpool_node (new_decl);
>>>> +  gcc_assert (vnode != NULL);
>>>> +  /* Set finalized to 1, otherwise it asserts in function "write_symbol" in
>>>> +     lto-streamer-out.c. */
>>>> +  vnode->finalized = 1;
>>>> +
>>>> +  return new_decl;
>>>> +}
>>>> +
>>>> +/* Traverses the chain of fields in STRUCT_TYPE and returns the FIELD_NUM
>>>> +   numbered field. */
>>>> +
>>>> +static tree
>>>> +get_field_from_struct (tree struct_type, int field_num)
>>>> +{
>>>> +  int i;
>>>> +  tree field = TYPE_FIELDS (struct_type);
>>>> +
>>>> +  for (i = 0; i < field_num; i++, field = DECL_CHAIN(field))
>>>> +    {
>>>> +      gcc_assert (field != NULL_TREE);
>>>> +    }
>>>> +
>>>> +  return field;
>>>> +}
>>>> +
>>>> +/* FNDECL is a __builtin_cpu_* call that is folded into an integer defined
>>>> +   in libgcc/config/i386/i386-cpuinfo.c */
>>>> +
>>>> +static tree
>>>> +fold_builtin_cpu (enum ix86_builtins fn_code)
>>>> +{
>>>> +  /* This is the order of bit-fields in __processor_features in
>>>> +     i386-cpuinfo.c */
>>>> +  enum processor_features
>>>> +  {
>>>> +    F_CMOV = 0,
>>>> +    F_MMX,
>>>> +    F_POPCNT,
>>>> +    F_SSE,
>>>> +    F_SSE2,
>>>> +    F_SSE3,
>>>> +    F_SSSE3,
>>>> +    F_SSE4_1,
>>>> +    F_SSE4_2,
>>>> +    F_MAX
>>>> +  };
>>>> +
>>>> +  /* This is the order of bit-fields in __processor_model in
>>>> +     i386-cpuinfo.c */
>>>> +  enum processor_model
>>>> +  {
>>>> +    M_AMD = 0,
>>>> +    M_INTEL,
>>>> +    M_INTEL_ATOM,
>>>> +    M_INTEL_CORE2,
>>>> +    M_INTEL_COREI7,
>>>> +    M_INTEL_COREI7_NEHALEM,
>>>> +    M_INTEL_COREI7_WESTMERE,
>>>> +    M_INTEL_COREI7_SANDYBRIDGE,
>>>> +    M_AMDFAM10H,
>>>> +    M_AMDFAM10H_BARCELONA,
>>>> +    M_AMDFAM10H_SHANGHAI,
>>>> +    M_AMDFAM10H_ISTANBUL,
>>>> +    M_AMDFAM15H_BDVER1,
>>>> +    M_AMDFAM15H_BDVER2,
>>>> +    M_MAX
>>>> +  };
>>>> +
>>>> +  static tree __processor_features_type = NULL_TREE;
>>>> +  static tree __cpu_features_var = NULL_TREE;
>>>> +  static tree __processor_model_type = NULL_TREE;
>>>> +  static tree __cpu_model_var = NULL_TREE;
>>>> +  static tree field;
>>>> +  static tree which_struct;
>>>> +
>>>> +  if (__processor_features_type == NULL_TREE)
>>>> +    __processor_features_type = build_struct_with_one_bit_fields (F_MAX,
>>>> +                                 "__processor_features");
>>>> +
>>>> +  if (__processor_model_type == NULL_TREE)
>>>> +    __processor_model_type = build_struct_with_one_bit_fields (M_MAX,
>>>> +                                 "__processor_model");
>>>> +
>>>> +  if (__cpu_features_var == NULL_TREE)
>>>> +    __cpu_features_var = make_var_decl (__processor_features_type,
>>>> +                                       "__cpu_features");
>>>> +
>>>> +  if (__cpu_model_var == NULL_TREE)
>>>> +    __cpu_model_var = make_var_decl (__processor_model_type,
>>>> +                                    "__cpu_model");
>>>> +
>>>> +  /* Look at the code to identify the field requested. */
>>>> +  switch (fn_code)
>>>> +    {
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_CMOV:
>>>> +      field = get_field_from_struct (__processor_features_type, F_CMOV);
>>>> +      which_struct = __cpu_features_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_MMX:
>>>> +      field = get_field_from_struct (__processor_features_type, F_MMX);
>>>> +      which_struct = __cpu_features_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT:
>>>> +      field = get_field_from_struct (__processor_features_type, F_POPCNT);
>>>> +      which_struct = __cpu_features_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE:
>>>> +      field = get_field_from_struct (__processor_features_type, F_SSE);
>>>> +      which_struct = __cpu_features_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE2:
>>>> +      field = get_field_from_struct (__processor_features_type, F_SSE2);
>>>> +      which_struct = __cpu_features_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE3:
>>>> +      field = get_field_from_struct (__processor_features_type, F_SSE3);
>>>> +      which_struct = __cpu_features_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSSE3:
>>>> +      field = get_field_from_struct (__processor_features_type, F_SSSE3);
>>>> +      which_struct = __cpu_features_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_1:
>>>> +      field = get_field_from_struct (__processor_features_type, F_SSE4_1);
>>>> +      which_struct = __cpu_features_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_2:
>>>> +      field = get_field_from_struct (__processor_features_type, F_SSE4_2);
>>>> +      which_struct = __cpu_features_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_AMD:
>>>> +      field = get_field_from_struct (__processor_model_type, M_AMD);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL:
>>>> +      field = get_field_from_struct (__processor_model_type, M_INTEL);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_ATOM:
>>>> +      field = get_field_from_struct (__processor_model_type, M_INTEL_ATOM);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_CORE2:
>>>> +      field = get_field_from_struct (__processor_model_type, M_INTEL_CORE2);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_INTEL_COREI7);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_INTEL_COREI7_NEHALEM);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_INTEL_COREI7_WESTMERE);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_INTEL_COREI7_SANDYBRIDGE);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_AMDFAM10H);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_AMDFAM10H_BARCELONA);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_AMDFAM10H_SHANGHAI);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_AMDFAM10H_ISTANBUL);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_AMDFAM15H_BDVER1);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2:
>>>> +      field = get_field_from_struct (__processor_model_type,
>>>> +                                    M_AMDFAM15H_BDVER2);
>>>> +      which_struct = __cpu_model_var;
>>>> +      break;
>>>> +    default:
>>>> +      return NULL_TREE;
>>>> +    }
>>>> +
>>>> +  return build3 (COMPONENT_REF, TREE_TYPE (field), which_struct, field, NULL_TREE);
>>>> +}
>>>> +
>>>> +static tree
>>>> +ix86_fold_builtin (tree fndecl, int n_args ATTRIBUTE_UNUSED,
>>>> +                  tree *args ATTRIBUTE_UNUSED, bool ignore ATTRIBUTE_UNUSED)
>>>> +{
>>>> +  const char* decl_name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
>>>> +  if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_MD
>>>> +      && strstr(decl_name, "__builtin_cpu") != NULL)
>>>> +    {
>>>> +      enum ix86_builtins code = (enum ix86_builtins)
>>>> +                               DECL_FUNCTION_CODE (fndecl);
>>>> +      return fold_builtin_cpu (code);
>>>> +    }
>>>> +  return NULL_TREE;
>>>> +}
>>>> +
>>>> +/* A builtin to init/return the cpu type or feature.  Returns an
>>>> +   integer and the type is a const if IS_CONST is set. */
>>>> +
>>>> +static void
>>>> +make_platform_builtin (const char* name, int code, int is_const)
>>>> +{
>>>> +  tree decl;
>>>> +  tree type;
>>>> +
>>>> +  type = ix86_get_builtin_func_type (INT_FTYPE_VOID);
>>>> +  decl = add_builtin_function (name, type, code, BUILT_IN_MD,
>>>> +                              NULL, NULL_TREE);
>>>> +  gcc_assert (decl != NULL_TREE);
>>>> +  ix86_builtins[(int) code] = decl;
>>>> +  if (is_const)
>>>> +    TREE_READONLY (decl) = 1;
>>>> +}
>>>> +
>>>> +/* Builtins to get CPU type and features supported. */
>>>> +
>>>> +static void
>>>> +ix86_init_platform_type_builtins (void)
>>>> +{
>>>> +  make_platform_builtin ("__builtin_cpu_init",
>>>> +                        IX86_BUILTIN_CPU_INIT, 0);
>>>> +  make_platform_builtin ("__builtin_cpu_supports_cmov",
>>>> +                        IX86_BUILTIN_CPU_SUPPORTS_CMOV, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_supports_mmx",
>>>> +                        IX86_BUILTIN_CPU_SUPPORTS_MMX, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_supports_popcount",
>>>> +                        IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_supports_sse",
>>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_supports_sse2",
>>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE2, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_supports_sse3",
>>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE3, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_supports_ssse3",
>>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSSE3, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_supports_sse4_1",
>>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE4_1, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_supports_sse4_2",
>>>> +                        IX86_BUILTIN_CPU_SUPPORTS_SSE4_2, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_amd",
>>>> +                        IX86_BUILTIN_CPU_IS_AMD, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_intel_atom",
>>>> +                        IX86_BUILTIN_CPU_IS_INTEL_ATOM, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_intel_core2",
>>>> +                        IX86_BUILTIN_CPU_IS_INTEL_CORE2, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_intel",
>>>> +                        IX86_BUILTIN_CPU_IS_INTEL, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7",
>>>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_nehalem",
>>>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_westmere",
>>>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_intel_corei7_sandybridge",
>>>> +                        IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10",
>>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_barcelona",
>>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_shanghai",
>>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam10_istanbul",
>>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam15_bdver1",
>>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1, 1);
>>>> +  make_platform_builtin ("__builtin_cpu_is_amdfam15_bdver2",
>>>> +                        IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2, 1);
>>>> +}
>>>> +
>>>>  /* Internal method for ix86_init_builtins.  */
>>>>
>>>>  static void
>>>> @@ -27529,6 +28143,9 @@ ix86_init_builtins (void)
>>>>
>>>>   ix86_init_builtin_types ();
>>>>
>>>> +  /* Builtins to get CPU type and features. */
>>>> +  ix86_init_platform_type_builtins ();
>>>> +
>>>>   /* TFmode support builtins.  */
>>>>   def_builtin_const (0, "__builtin_infq",
>>>>                     FLOAT128_FTYPE_VOID, IX86_BUILTIN_INFQ);
>>>> @@ -29145,6 +29762,48 @@ ix86_expand_builtin (tree exp, rtx target, rtx sub
>>>>   enum machine_mode mode0, mode1, mode2, mode3, mode4;
>>>>   unsigned int fcode = DECL_FUNCTION_CODE (fndecl);
>>>>
>>>> +  /* For CPU builtins that can be folded, fold first and expand the fold.  */
>>>> +  switch (fcode)
>>>> +    {
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_CMOV:
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_MMX:
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_POPCOUNT:
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE:
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE2:
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE3:
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSSE3:
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_1:
>>>> +    case IX86_BUILTIN_CPU_SUPPORTS_SSE4_2:
>>>> +    case IX86_BUILTIN_CPU_IS_AMD:
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL:
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_ATOM:
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_CORE2:
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7:
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_NEHALEM:
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_WESTMERE:
>>>> +    case IX86_BUILTIN_CPU_IS_INTEL_COREI7_SANDYBRIDGE:
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H:
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_BARCELONA:
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_SHANGHAI:
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM10H_ISTANBUL:
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER1:
>>>> +    case IX86_BUILTIN_CPU_IS_AMDFAM15H_BDVER2:
>>>> +      {
>>>> +        tree fold_expr = fold_builtin_cpu ((enum ix86_builtins) fcode);
>>>> +       gcc_assert (fold_expr != NULL_TREE);
>>>> +        return expand_expr (fold_expr, target, mode, EXPAND_NORMAL);
>>>> +      }
>>>> +    case IX86_BUILTIN_CPU_INIT:
>>>> +      {
>>>> +       /* Make it call __cpu_indicator_init in libgcc. */
>>>> +       tree call_expr, fndecl, type;
>>>> +        type = build_function_type_list (integer_type_node, NULL_TREE);
>>>> +       fndecl = build_fn_decl ("__cpu_indicator_init", type);
>>>> +       call_expr = build_call_expr (fndecl, 0);
>>>> +       return expand_expr (call_expr, target, mode, EXPAND_NORMAL);
>>>> +      }
>>>> +    }
>>>> +
>>>>   /* Determine whether the builtin function is available under the current ISA.
>>>>      Originally the builtin was not created if it wasn't applicable to the
>>>>      current ISA based on the command line switches.  With function specific
>>>> @@ -38610,6 +39269,12 @@ ix86_autovectorize_vector_sizes (void)
>>>>  #undef TARGET_BUILD_BUILTIN_VA_LIST
>>>>  #define TARGET_BUILD_BUILTIN_VA_LIST ix86_build_builtin_va_list
>>>>
>>>> +#undef TARGET_FOLD_BUILTIN
>>>> +#define TARGET_FOLD_BUILTIN ix86_fold_builtin
>>>> +
>>>>  #undef TARGET_ENUM_VA_LIST_P
>>>>  #define TARGET_ENUM_VA_LIST_P ix86_enum_va_list
>>>> Index: gcc/testsuite/gcc.target/i386/builtin_target.c
>>>> ===================================================================
>>>> --- gcc/testsuite/gcc.target/i386/builtin_target.c      (revision 0)
>>>> +++ gcc/testsuite/gcc.target/i386/builtin_target.c      (revision 0)
>>>> @@ -0,0 +1,61 @@
>>>> +/* This test checks if the __builtin_cpu_* calls are recognized. */
>>>> +
>>>> +/* { dg-do run } */
>>>> +
>>>> +int
>>>> +fn1 ()
>>>> +{
>>>> +  if (__builtin_cpu_supports_cmov () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_supports_mmx () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_supports_popcount () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_supports_sse () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_supports_sse2 () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_supports_sse3 () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_supports_ssse3 () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_supports_sse4_1 () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_supports_sse4_2 () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_amd () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_intel () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_intel_atom () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_intel_core2 () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_intel_corei7 () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_intel_corei7_nehalem () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_intel_corei7_westmere () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_intel_corei7_sandybridge () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_amdfam10 () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_amdfam10_barcelona () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_amdfam10_shanghai () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_amdfam10_istanbul () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_amdfam15_bdver1 () < 0)
>>>> +    return -1;
>>>> +  if (__builtin_cpu_is_amdfam15_bdver2 () < 0)
>>>> +    return -1;
>>>> +
>>>> +  return 0;
>>>> +}
>>>> +
>>>> +int main ()
>>>> +{
>>>> +  return fn1 ();
>>>> +}
>>>>
>>>> --
>>>> This patch is available for review at http://codereview.appspot.com/5754058